CD−Writing HOWTO
CD−Writing HOWTO
Table of Contents
CD−Writing HOWTO........................................................................................................................................1
Winfried Trümper <winni@xpilot.org>..................................................................................................1
1.Introduction...........................................................................................................................................1
2.Setup the Linux−system for writing CD−ROMs..................................................................................1
3.Burning CD−Rs....................................................................................................................................1
4.Dear Winfried,......................................................................................................................................1
5.Troubleshooting....................................................................................................................................2
6.Credits...................................................................................................................................................2
1.Introduction...........................................................................................................................................2
1.1 Copyright, license and terms of usage...............................................................................................3
1.2 Availability........................................................................................................................................3
1.3 Suggested readings.............................................................................................................................3
1.4 Terminology ... lasers at maximum ... fire!........................................................................................4
Adaptor vs. Adapter....................................................................................................................4
1.5 Supported CD−writers.......................................................................................................................4
1.6 Supported "features"..........................................................................................................................6
1.7 Mailing Lists......................................................................................................................................7
2.Setup the Linux−system for writing CD−ROMs..................................................................................8
2.1 Quickstart...........................................................................................................................................9
Special notes about SCSI CD−writers......................................................................................12
Special notes about CD−writers for the parallel port...............................................................12
Compiling missing kernel modules (optional)..........................................................................12
2.2 Get the user software for burning CD−Rs.......................................................................................13
Command line utilities..............................................................................................................13
Graphical user interfaces (optional)..........................................................................................14
3.Burning CD−Rs..................................................................................................................................15
3.1 Writing CD−ROMs (pure data).......................................................................................................15
Creating an image of the later CD−ROM.................................................................................15
Test the CD−image...................................................................................................................16
Write the CD−image to a CD...................................................................................................17
3.2 Writing audio CDs...........................................................................................................................18
Writing audio CDs (TAO)........................................................................................................19
DAO..........................................................................................................................................20
3.3 Mixed mode CD−ROMs..................................................................................................................20
4.Dear Winfried,....................................................................................................................................20
4.1 How sensitive is the burning process?.............................................................................................21
4.2 Has file fragmentation a bad impact on the throughput?.................................................................21
4.3 Is it possible to store the CD−image on an UMSDOS−filesystem?................................................21
4.4 Isn't there some way to get around the ISO−9660 limitations?.......................................................22
4.5 How to read the tracks from audio CDs?.........................................................................................22
4.6 How to probe for SCSI devices after boot?.....................................................................................23
4.7 Is it possible to make a 1:1 copy of a data CD?...............................................................................23
4.8 Can Linux read Joliet CD−ROMs? (obsolete answer)....................................................................24
4.9 How do I read/mount CD−ROMs with the CD−writer?..................................................................24
4.10 How to put even more data on the CD−R?....................................................................................25
4.11 How to make bootable CD−ROMs?..............................................................................................25
4.12 How to make CD−ROMs writable like a hard disk?.....................................................................26
i
CD−Writing HOWTO
Table of Contents
4.13 Is it possible to use several writers at once?..................................................................................26
4.14 What about Solaris, *BSD, AIX, HP−UX, etc.? Is my variant of Unix supported?.....................26
4.15 Where to store the local configuration permanently?....................................................................27
4.16 How can the CD−info be retrieved?..............................................................................................28
4.17 What about re−writing...................................................................................................................28
4.18 How to create a multi−session CD?...............................................................................................28
4.19 Should I use the SCSI adapter shipped with the writer?................................................................29
4.20 How to burn over the network?.....................................................................................................29
4.21 I hear a crack or click sound at the end of the each track..............................................................30
4.22 How can this be set up so that a user can burn CDs instead of always being root?......................30
4.23 Where do I get the "Yellow Book" and "Orange Book" standards?..............................................30
4.24 I've been searching for information on burning Video−CD under Linux......................................30
4.25 Which is easier to set up, IDE or SCSI?........................................................................................31
4.26 How can I overburn a CD using {cdrecord,cdrdao}?....................................................................31
4.27 What will cdrecord do when it stops getting input from the pipe?................................................31
4.28 Is there an equivalent to ignore=hdX for the ide−scsi emulation?................................................31
4.29 How many times can you re−use CD−RW before they become faulty?.......................................31
4.30 Which format to choose for a platform independant CD−ROM?.................................................32
4.31 Is multi−session for audio tracks possible?...................................................................................32
4.32 What hardware resources do I need? Is an old Pentium enough?..................................................32
5.Troubleshooting..................................................................................................................................32
5.1 It doesn't work: under Linux............................................................................................................33
5.2 Error−message: No read access for 'dev=0,6,0'...............................................................................33
5.3 It doesn't work: under DOS and friends...........................................................................................33
5.4 SCSI errors during the burning phase..............................................................................................33
5.5 Medium errors If cdrecord reports medium errors in the form of"Sense Key: ... Medium Error, Segment
4
..."
5.6 Newly written CDs are not readable on some players.....................................................................34
5.7 My scanner stopped working after I loaded the ide−scsi module....................................................34
6.Credits.................................................................................................................................................35
ii
CD−Writing HOWTO
Winfried Trümper <winni@xpilot.org>
v2.9.3, 23 July 2000
This document explains how to write CD−ROMs under Linux.
1.Introduction
• 1.1 Copyright, license and terms of usage
• 1.2 Availability
• 1.3 Suggested readings
• 1.4 Terminology ... lasers at maximum ... fire!
• 1.5 Supported CD−writers
• 1.6 Supported "features"
• 1.7 Mailing Lists
2.Setup the Linux−system for writing CD−ROMs
• 2.1 Quickstart
• 2.2 Get the user software for burning CD−Rs
3.Burning CD−Rs
• 3.1 Writing CD−ROMs (pure data)
• 3.2 Writing audio CDs
• 3.3 Mixed mode CD−ROMs
4.Dear Winfried,...
• 4.1 How sensitive is the burning process?
• 4.2 Has file fragmentation a bad impact on the throughput?
• 4.3 Is it possible to store the CD−image on an UMSDOS−filesystem?
• 4.4 Isn't there some way to get around the ISO−9660 limitations?
• 4.5 How to read the tracks from audio CDs?
• 4.6 How to probe for SCSI devices after boot?
CD−Writing HOWTO
1
CD−Writing HOWTO
• 4.7 Is it possible to make a 1:1 copy of a data CD?
• 4.8 Can Linux read Joliet CD−ROMs? (obsolete answer)
• 4.9 How do I read/mount CD−ROMs with the CD−writer?
• 4.10 How to put even more data on the CD−R?
• 4.11 How to make bootable CD−ROMs?
• 4.12 How to make CD−ROMs writable like a hard disk?
• 4.13 Is it possible to use several writers at once?
• 4.14 What about Solaris, *BSD, AIX, HP−UX, etc.? Is my variant of Unix supported?
• 4.15 Where to store the local configuration permanently?
• 4.16 How can the CD−info be retrieved?
• 4.17 What about re−writing
• 4.18 How to create a multi−session CD?
• 4.19 Should I use the SCSI adapter shipped with the writer?
• 4.20 How to burn over the network?
• 4.21 I hear a crack or click sound at the end of the each track.
• 4.22 How can this be set up so that a user can burn CDs instead of always
• 4.23 Where do I get the "Yellow Book" and "Orange Book" standards?
• 4.24 I've been searching for information on burning Video−CD under Linux.
• 4.25 Which is easier to set up, IDE or SCSI?
• 4.26 How can I overburn a CD using {cdrecord,cdrdao}?
• 4.27 What will cdrecord do when it stops getting input from the pipe?
• 4.28 Is there an equivalent to ignore=hdX for the ide−scsi emulation?
• 4.29 How many times can you re−use CD−RW before they become faulty?
• 4.30 Which format to choose for a platform independant CD−ROM?
• 4.31 Is multi−session for audio tracks possible?
• 4.32 What hardware resources do I need? Is an old Pentium enough?
5.Troubleshooting
• 5.1 It doesn't work: under Linux
• 5.2 Error−message: No read access for 'dev=0,6,0'.
• 5.3 It doesn't work: under DOS and friends
• 5.4 SCSI errors during the burning phase
• 5.5 Medium errors
• 5.6 Newly written CDs are not readable on some players.
• 5.7 My scanner stopped working after I loaded the ide−scsi module
6.Credits
1.Introduction
Many people use Linux to burn CD−ROMs, because it is reliable and easy. No bluescreens while burning and
no headaches about getting the right combination of hard− and software. It just works once properly set up.
The CD−writing HOWTO explains the setup, how to put data on the media and gives some interesting
5.Troubleshooting
2
CD−Writing HOWTO
applications kindly submitted by the readers.
1.1 Copyright, license and terms of usage
Copyright Winfried Trümper 1996−2000. All rights reserved.
Redistribution and use, with or without modification, are permitted provided that the name of the author may
not be used to endorse or promote products derived from this software without specific prior written
permission. In this sense, translations are welcome and need not to be authorized by me.
The author disclaims all warranties with regard to this document, including all implied warranties of
merchantability and fitness for a certain purpose; in no event shall the author be liable for any special,
indirect or consequential damages or any damages whatsoever resulting from loss of use, data or
profits, whether in an action of contract, negligence or other tortious action, arising out of or in
connection with the use of this document.
Short: read and use at your own risk. No money−back guarantee. If you want to understand why this
document has always been under a very weak license and not under the gnu GPL or similar restrictive, then
you should read this article from the german computer magazine c't:
http://www.heise.de/tp/deutsch/inhalt/te/8375/1.html (currently only in German language).
1.2 Availability
As the editor of this document I mostly sum up what other people report to me. I'm not a software developer
nor an expert in hardware, so for specific problems with hard− or software you may want to ask somebody
else. What always makes sense is to report solutions for problems not already covered by the HOWTO to me.
I get several hundred e−mails concerning the CD−Writing HOWTO each year. So please be patient with me,
as I cannot always answer within hours. However, I read everything immediately and put you on my
CDR−queue. Before you ask a question, please make sure you are aware of the newest version of this
document; it is always available from http://www.guug.de/~winni/linux/.
1.3 Suggested readings
You may need the handbook for your Linux−distribution to learn about installing a new kernel. I'm really
clueless about this issue when it comes to any other Linux distribution than my own.
The CD−R FAQ is a general FAQ about compact−disk recordables (CD−R), CD−writers and the required
1.1 Copyright, license and terms of usage
3
CD−Writing HOWTO
software. As most CD−writers can be used to read CD−ROMs, too, you may want to read the Linux
CD−ROM HOWTO, the Linux SCSI HOWTO and the Linux Kernel HOWTO.
1.4 Terminology ... lasers at maximum ... fire!
CD−ROM stands for Compact Disc Read Only Memory, a storage medium utilizing an optical laser to sense
microscopic pits on a colorful shimmering disk. The pits represent the bits of the information and are so
petite that some billions of them fit on the disc. Thus a CD is a mass−storage medium.
The term CD−R is a short form of CD−ROM recordable and refers to a CD that doesn't have those
microscopic pits on its surface. Thus it is empty. The CD−R has a special chemical film inside into which pits
can be burned. This is done by giving the laser which normally just senses the pits a little bit more power so it
burns the pits. This action can only be taken once on a CD−R. You can leave out some areas for later writing,
creating a so called multi−session CD.
The CD−ROM rewritable (short: CD−RW) was developed to work around the limitation of CD−R media.
With a CD−RW burner the laser can do both, burn pits into the media and also melt the media back into its
original state. This is possible, because the laser does not really burn holes into the media, which would get
lost in a puff of smoke. A decent analogy for the technique is an ice−hockey game: by driving over the ice, a
players (laser) leave scratches in it. The pattern in the ice (media) is a recording of what happened on the ice
during one round. In between the periods of the game, the Zamboni cleaning car drives over the ice and fills
the scratches by melting the very top layer of the ice. (Zamboni is the brand name for cleaning cars in
ice−hockey stadiums). This way the pattern on the ice is cleared and a new round can begin. The scientific
term for evaporating, condensing, melting and freezing is "phase change", thus the name "phase change
devices" for CD−RW−writers.
This HOWTO deals with the task of writing CD−Rs and CD−RWs. Welcome on board, captain.
Adaptor vs. Adapter
The the most frequent spelling within the kernel sources is adapter (adapter: 4283, adaptor: 154). Even more
important, the parameters of module options and aliases are naturally affected, like in "scsi_hostadapter". So
in order to achieve a consistent spelling throughout configuration examples and document text, I follow that
convention regardless of the correct spelling.
1.5 Supported CD−writers
USB CD−writers are currently not supported at all. Apart from that you can safely assume that most newer
IDE/ATAPI− and SCSI−writers work under Linux. Newer drives are mostly MMC−compliant and are
therefore supported. If the SCSI−version of a particular writer works, the IDE/ATAPI−version will most
likely work and vice versa. However, some people want to get a warm and fuzzy feeling by reading the exact
model of their writer in some sort of compatibility list. That is the reason why I didn't throw the following list
1.4 Terminology ... lasers at maximum ... fire!
4
CD−Writing HOWTO
out of the HOWTO. Here is a comprehensive summary of drives reported to work with cdrecord:
Acer:
BTC:
Compro:
Creative:
Delta:
Dysan:
Elite:
Goldstar:
Grundig:
Guillemot:
HP:
Hi−Val:
Iomega:
JVC:
Kiss:
Kodak:
Matsushita:
Memorex:
Microboards:
MicroNet:
Mitsubishi:
Mitsumi:
Nomai:
Olympus:
Optima:
OTI:
Panasonic:
Philips:
Pinnacle:
Pioneer:
Plasmon:
Plextor:
Procom:
REC:
Ricoh:
Samsung:
Sanyo:
Smart and
Friendly:
Sony:
Taiyo Yuden:
TEAC:
CDRW 4432A, CDRW 6206A, CD−R/RW 6X4X32, 8432A
BCE 621E (IDE)
CW−7502, CW−7502B
MK 4211, RW 4224E,
OME−W 141
CRW−1622
Elite b444.41
CED−8041B
CDR 100 IPW
Maxi CD−R 4X/8X
SureStore 4020i, SureStore 6020i,
C4324, C4325
CD−writer+ 7100, 7200i, 7500e, 8100i, 8110i, 8200i Plus,
8250i, 9100i, 9110i, 9200e, 9210, 9300i, 9310i
CDD 2242, CDD−3610,
ZIPCD 4x650
XR−W 2001, XR−W 2010, XR−W 2040, XR−W 2042, XR−RW 2224,
YR 2626
CDRW (no model given)
PCD 200, PCD 225, PCD 260, PCD 600
matsushita is the japanese name for panasonic, please see there
CRW−620, CDR−622, CRW−1622, CRW−2224, CDRW−4420
PlayWrite 2000, PlayWrite 4000 RW, PlayWrite 4001 RW
MasterCD Plus 4x4, MasterCD Plus 4x6
CDRW−226
CR−2401−TS, CR−2600 TE, CR−2801 TE,
CR−4801 TE, CR−4802 TE, CR−4804 TE
680.RW
CDS 615E, CDS 620E
DisKovery 650 CD−R
CDRW 965, CDRW 975 (Socrates 1.0)
CW−7285, CW−7502, CW−7503, CW−7582
CDD−521/10, CDD−522,
CDD−2000, CDD−2600, CDD−3600, CDD−3610, CDD 4201
PCA 267cr, PCA 460 RW, PCRW 404,
Omniwriter 26, Omniwriter 26A,
CDRW800
RCD−100, RCD−1000, RCD−5020, RCD−5040
DW−S114X
CDR 480, CDR 4220, RF−4100, RF−4102, CDR 4400
CDR PX−24 CS, PX−412 C, PX−R412 C
PX−R 810Ti, PX−R 820T, PX−W 4220Ti, PX−W 8220T, PX−W 8432T
Plexwriter RW 4/2/20
PCDR 4
820s
RO−1420C+, MP 1420C, MP 6200S, MP 6201S, MP 7040A, MP−7060A
SW−204
CRD−R24S
CD−RW 226, CD−R 1002, CD−R 1002/PRO, CD−R 1004,
CD−R 2004, CD−R 2006 PLUS, CD−R 2006 PRO, CD−RW 2224,
CD−R 4000, CD−R 4006, CD−R 4012, CD−RW 4424A
CD−R 8020, CD−R 8220
CDRX 100E, CDRX 120E, CDRX 140S−RP,
CDU 920S, CDU 924, CDU 926S, CDU 928E, CDU 948S
EW−50
CD−R50S, CD−R55S, CDR−55S, CDR−55K,
1.4 Terminology ... lasers at maximum ... fire!
5
CD−Writing HOWTO
Traxdata:
Turtle Beach:
Waitec:
WPI (Wearnes):
Yamaha:
CDR−56S−400, CD−R56S−600, R56S−614
CRW 2260,
CDR 4120, CDR 4120 Pro, CDRW 4260, CDRW 4424, CDR 4800
2040R
wt 2036, wt 2444ei
CDRW−622, CDR−632P
CDR−100, CDR 102, CDR−200, CDR−200t, CDR−200tx
CDR−400, CDR−400c, CDR−400t, CDR−400tx, CDR−400Atx
CDW−2216E, CRW−2260, CRW−2260t,
CRW−4250tx, CRW−4260t, CRW−4260tx, CRW−4261, CRW−4416S,
CRW−6416S, CRW−8424E
Table: CD−writers supported under Linux
The detailed list of models which have been reported to work or not to work under various Unix−like
operating systems is available online from http://www.guug.de:8080/cgi−bin/winni/lsc−orig.pl.
If your hardware isn't supported you can still use Linux to create an image of the CD. You may wish to do so
because most burning software for DOS does not deal with RockRidge−extensions (Unix−like filesystems on
CD−ROM). In a second step, you can use DOS or Macintosh software to write the image to the CD−R.
1.6 Supported "features"
Two There are two classes of utilities: the hardware drivers and the data−formatters. The hardware drivers
support the following features:
Supported Feature
cdwrite−2.1
cdrecord−1.6
cdrdao
−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
IDE/ATAPI
yes
yes
yes
Parallel Port
no
yes
yes
CD−RW
no
yes
yes
Audio CD
yes
yes
yes
Data CD−ROM
yes
yes
partial
Multisession
partial
yes
no
TAO (track at once) yes
yes
yes
DAO (disk at once) no
partial
yes
packet writing
no
no
no
Table:
cdwrite is unmaintained software referenced only for completeness. Please use cdrecord instead, as it
supports a wider range of hardware and has significantly more features. The main benefit of cdrdao is the
ability to create audio CDs without two seconds of silence between the tracks (writing in disk−at−once
(DAO) mode).
The tools classified as "data−formatters" organize the data on the media ("put a filesystem on it").
1.6 Supported "features"
6
CD−Writing HOWTO
Feature
mkisofs
mkhybrid
mkvcdfs
−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
ISO 9660
yes
yes
no
RockRidge
yes
yes
no
El Torito
yes
yes
no
HFS
no
yes
no
Joliet
yes
yes
no
Multisession
yes
yes
no
CD−Extra
yes
yes
no
Video−CD
no
no
yes
Table:
The most obvious difference between the ISO 9660 filesystem compared to the ReiserFS or Extended−2
filesystem is: you can't modify files once they are written. Other limitations of the ISO−9660−filesystem
include:
• only 8 levels of sub−directories allowed (counted from the top−level directory of the CD)
• maximum length for filenames: 32 characters
• 650 MB capacity
RockRidge is an extension to allow longer filenames and a deeper directory hierarchy for the ISO−9660
filesystem. When reading a CD−ROM with RockRidge extensions under Linux, all the known properties of
files like owner, group, permissions, symbolic links appear ("feels like a Unix filesystem"). These extensions
are not available when reading the CD−ROM under DOS or the heterogenous Windows−family of operating
systems.
El Torito can be used to produce bootable CD−ROMs. For this feature to work, the BIOS of your PC must
support it. Roughly speaking, the first 1.44 (or 2.88 if supported) Mbytes of the CD−ROM contains a
floppy−disk image supplied by you. This image is treated like a floppy by the BIOS and booted from. (As a
consequence, while booting from this virtual floppy, your original drive A: (/dev/fd0) may not be accessible.)
HFS lets a Macintosh read the CD−ROM as if it were an HFS volume (the native filesystem for MacOS).
Joliet brings long filenames (among other things) to newer variants of Windows (95, 98, NT). However, the
author knows of no tool that allows long filenames under plain DOS or Windows 3.11.
Video−CDs can be directly played on DVD−devices.
Section 2.8 lists the availability of the mentioned software.
1.7 Mailing Lists
If you want to join the development team (with the intention to actively help them), send e−mail to
cdwrite−request@other.debian.org and put the word subscribe in body of the message.
1.7 Mailing Lists
7
CD−Writing HOWTO
2.Setup the Linux−system for writing CD−ROMs
This section applies to the following types of CD−writers: SCSI, IDE/ATAPI and the devices for the parallel
port. USB CD−writers are not supported as of May 2000. Non−SCSI writers require compatibility drivers,
which make them appear as if they were real SCSI devices. On the one side such a unifying strategy is easy
("everything is SCSI"), because on the application level you can share your knowledge with other users
regardless of their kind of CD−writer. On the other side, you have to reconfigure applications like audio CD
players or the mount utility to reflect the change of the driver name. For example, if you accessed your
ATAPI CD−writer through the device file /dev/hdc before, you will have to access it through /dev/scd0 after
activating the SCSI compatibility drivers.
Once you succeed setting up your hardware and the rest of your Linux−system, the command cdrecord
−scanbus shows you a list of devices on your SCSI busses. The goal of this section is to guide you in
setting up your Linux−system, so that you finally end up seeing something like:
shell> cdrecord −scanbus
Cdrecord release 1.7a1 Copyright (C) 1995−1998 Jörg Schilling
scsibus0:
0,0,0) 'Quantum ' 'XP34300
' 'F76D' Disk
0,1,0) 'SEAGATE ' 'ST11200N
' '8334' Disk
0,2,0) *
0,3,0) 'TOSHIBA ' 'MK537FB/
' '6258' Disk
0,4,0) 'WANGTEK ' '5150ES SCSI 36 ' 'ESB6' Removable Tape
0,5,0) 'EXABYTE ' 'EXB−8500−85QUE ' '0428' Removable Tape
0,6,0) 'TOSHIBA ' 'XM−3401TASUNSLCD' '3593' Removable CD−ROM
0,7,0) *
scsibus1:
1,0,0) 'Quantum ' 'XP31070W
' 'L912' Disk
1,1,0) *
1,2,0) *
1,3,0) 'TEAC
' 'CD−R55S
' '1.0H' Removable CD−ROM
1,4,0) 'MATSHITA' 'CD−R
CW−7502 ' '4.02' Removable CD−ROM
1,5,0) *
1,6,0) 'YAMAHA ' 'CDR400t
' '1.0d' Removable CD−ROM
1,7,0) *
Listing: Detecting devices on your SCSI bus
The example was provided by Jörg Schilling and shows a total of four CD−writers. Please note that −scanbus
also reports other devices, e.g. regular CD−ROMs and hard disk drives. The last column gives the SCSI
description of the device, from which you cannot clearly distinguish ordinary CD−ROM drives from those
with burning capability. But the product identification (middle column) often has hints about the feature in
form of a R, −R or −RW.
2.Setup the Linux−system for writing CD−ROMs
8
CD−Writing HOWTO
2.1 Quickstart
This section is an attempt to provide an fast and easy description of the configuration. Not all possible setups
are covered, but please go on and try it out anyways. First of all, check the Linux kernel version printed by
the command "uname −r". It should be something like 2.0.X or 2.2.Y, where X is higher than 36 and Y is
higher than 11. If you run older versions or the so called development kernels, you are on your own.
Installing a new kernel is as much work as fixing an old one, so I have removed all hints you need for buggy
kernels.
The listing below shows a set of commands you could start with. The commands create device file entries
under /dev unless they already exists.
test `whoami` = 'root' || echo "You must be root to execute the commands."
cd /dev/
umask −S u=rwx,g=rwx,o−rwx
[ −f loop0 ] \
|| ./MAKEDEV loop \
|| for i in 0 1 2 3 4 5 6 7; do mknod loop$i b 7 $i; done
[ −f sg0 −o −f sga ] \
|| ./MAKEDEV sg \
|| for i in 0 1 2 3 4 5 6 7; do mknod sg$i c 21 $i; done
Listing: creating of devicefiles
Hardware access is usally implemented through device files under Linux. So before any other thing you make
sure those files do exists in the directory /dev. Still nobody could give me a compelling reason why this has
not been automated through techniques like the device filesystem (devfs). The devfs is available for years
know, brings a safer (!) and a far clearer naming of devices and makes the device entries appear automatically
under /dev. Some prominent people argue devfs is not the perfect solution, but they do not come up with
anything better, not even something comparable and last but least nothing available and tested now. Lets start
to use devfs, so I can remove the above commands from this document. (
http://www.atnf.CSIRO.AU/~rgooch/linux/kernel−patches.html)
Next thing to ensure is, that the Linux kernel is equiped with the necessary drivers. The following commands
check various files for the presence of drivers in the running Linux kernel. Usally the command "cdrecord
−scanbus" should trigger an automatic loading of all drivers. In case a driver is not present in the kernel
afterwards, it is reported and the modularized driver (module) is manually loaded through insmod.
test `whoami` = 'root' || echo "You must be root to execute the commands."
cdrecord −scanbus > /dev/null
if ! (pidof kerneld || test −f "/proc/sys/kernel/modprobe"); then
echo "Neither kerneld nor kmod are running to automatically load modules".
fi
report_no_autoload() {
echo "Ensure the module $1 is loaded automatically next time."
}
if test ! −f "/proc/scsi/scsi"; then
report_no_autoload scsi_mod && insmod scsi_mod
2.1 Quickstart
9
CD−Writing HOWTO
fi
if ! grep "^........ sg_" /proc/ksyms > /dev/null; then
report_no_autoload sg && insmod sg
fi
if ! grep "^........ sr_" /proc/ksyms > /dev/null; then
report_no_autoload sr_mod && insmod sr_mod
fi
if ! grep "^........ loop_" /proc/ksyms > /dev/null; then
report_no_autoload loop && insmod loop
fi
if ! grep iso9660 /proc/filesystems > /dev/null; then
report_no_autoload iso9660 && insmod iso9660
fi
echo "The following is only needed for IDE/ATAPI CD−writers."
if ! grep ide−scsi /proc/ide/drivers > /dev/null; then
report_no_autoload ide−scsi && insmod ide−scsi
fi
cdrecord −scanbus
Listing: Testing for drivers
Please read the next chapter if insmod complains about missing module files. If you are in text mode
(console), the loading of modules may cause some messages to be printed on your screen. If you are in
graphics mode (X11, KDE, Gnome), you can recall these messages with the command dmesg.
There are several ways to load the modules next time you start up your Linux system:
(1) Put the relevant insmod command into the startup sequence
(a shell script named rc.local or equivalent).
(2a) Run kerneld or kmod and
(2b) configure them in /etc/modules.conf (to be more precise,
you configure the utility modprobe, which is called by the daemons)
People with a SCSI−writer can skip the rest of this section, because cdrecord will most likely already detect
their hardware. If not, then please send me an email with some information about your setup, so I can
improve the section about SCSI−writers.
Now to the people with CD−writers for IDE/ATAPI. As written in the previous chapter, you have to load the
compatibility driver ide−scsi. But this driver can only access your CD−Writer if no other driver has already
done so. In other words, you have to tell the regular IDE driver to leave your CD−writer unrecognized, so the
ide−scsi driver can grab it.
hda
hdb
hdc
hdd
=
=
=
=
IDE
IDE
IDE
IDE
bus/connector
bus/connector
bus/connector
bus/connector
0
0
1
1
master
slave
master
slave
device
device
device
device
Table: device file names of IDE/ATAPI devices
2.1 Quickstart
10
CD−Writing HOWTO
The table above shows the relation of device file names and the placing of devices on the IDE busses. The
device file name representing your CD−Writer has to be passed to the driver in the Linux kernel. Example:
hdb=ide−scsi. Such a setting should be added to lilo.conf or chos.conf if the driver is statically compiled into
your kernel, which seems to be the most common setup. If you need to pass more than one parameter to the
kernel, then seperate them with spaces (like shown in the chos example). The next two listings show example
configurations containing more lines than just the relevant append−line. Please note the append− and
cmdline−entries are image−specific (ie. don't add them immediatly at the top).
image=/boot/zImage−2.2.14
label=Linux
read−only
append="hdb=ide−scsi"
Listing: Example configuration for lilo (/etc/lilo.conf)
linux "Linux 2.1.14" {
image=/boot/zImage−2.0.37
cmdline= root=/dev/hda5 readonly hdb=ide−scsi
}
Listing: Example configuration for chos (/etc/chos.conf)
If the driver for IDE/ATAPI CD−ROMs is loaded as a module, then the above won't make any difference to
you, but make sure you include the options−line from the next listing. The last three lines of that listing are
generally suggested to further automate the loading of the required modules.
options ide−cd ignore=hdb
alias scd0 sr_mod
#pre−install ide−scsi modprobe imm
pre−install sg
modprobe ide−scsi
pre−install sr_mod modprobe ide−scsi
pre−install ide−scsi modprobe ide−cd
# tell the ide−cd module to ignore hdb
# load sr_mod upon access of scd0
# uncomment for some ZIP drives only
# load ide−scsi before sg
# load ide−scsi before sr_mod
# load ide−cd
before ide−scsi
Listing: Example configuration for /etc/modules.conf
If your CD−writer is the only CD−ROM attached to your machine, then remember you have to access the
CD−ROM in the writer through the device file /dev/scd× where ×=0,..,8. You may want to change the
symbolic name cdrom to point to the new device file name. The listing below shows the command to achieve
this with the example scd0.
cd /dev && rm cdrom && ln −s scd0 cdrom
Listing: Making cdrom a symbolic name for scd0
If your CD−writer and CD−ROM−drive are two different devices, then don't change the cdrom symlink.
2.1 Quickstart
11
CD−Writing HOWTO
Special notes about SCSI CD−writers
Please make sure that your writer is recognized by the BIOS of your SCSI hostadaptor card. Every SCSI
hostadaptor scans the SCSI bus after power on and reports all devices found connected to the bus. The report
includes the SCSI ID of the devices and their product label. It makes no sense to proceed unless your CD
writer is listed in that report.
If you plan to connect your SCSI device through the parallel port (not to confuse with the IDE drives for the
parallel port), you need a special active cable and a special kernel driver. Read
http://www.torque.net/parport/parscsi.html to learn more about this option.
Special notes about CD−writers for the parallel port
I have no clue about this, sorry. Please read http://www.torque.net/parport/paride.html or your local file
/usr/src/linux/Documentation/paride.txt.
Compiling missing kernel modules (optional)
You don't need to read this section if you hardware is already sucessfully recognized and configured by the
previously described configuration steps.
The Linux kernel can be equipped with drivers for various features. You can compile the drivers into the
kernel image statically or you can compile them as a module for on−demand loading. The last method is
preferred for drivers not essential for bringing your Linux−system into life, because your kernel will be
smaller and faster then. However, some drivers are essential for the system to come up and you shouldn't
compile them as a module. Example: if your system lives on an IDE hard disk, you must have the driver for
IDE hard disks in the kernel −− not as a module.
There are three different types of CD−writers: SCSI, IDE/ATAPI and external writers that work through the
parallel port. The table shows how to configure the Linux kernel for those hardware types. The first column
of the table is the section of the kernel configuration menu, where you can find the setting. The second
column is the description of the feature (taken from the kernel configuration menu, too). The third column
gives the name of the resulting module. The columns named SCSI, IDE and PP contain the necessary options
for the associated hardware (PP = parallel port).
Sect. Description
Module
SCSI IDE
PP
−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
BLOCK Enhanced IDE/MFM/RLL...
Y
BLOCK IDE/ATAPI CDROM
ide−cd
M
BLOCK SCSI emulation support
ide−scsi
M
BLOCK Loopback device
loop
M
M
M
PARIDE Parallel port IDE device
Special notes about SCSI CD−writers
paride
Y/M
12
CD−Writing HOWTO
PARIDE Parallel port ATAPI CD−ROMs
PARIDE Parallel port generic ATAPI
PARIDE (select a low−level driver)
M
M
Y
SCSI
SCSI
SCSI
SCSI
SCSI
SCSI support
scsi_mod
SCSI CD−ROM support
sr_mod
Enable vendor−specific
SCSI generic support
sg
(select a low−level driver)
Y/M
Y/M
Y
Y/M
Y
Y/M
Y/M
Y
Y/M
FS
FS
ISO 9660 CDROM filesystem
Microsoft Joliet cdrom...
Y/M
Y
Y/M
Y
iso9660
joliet
Y/M
Y
Table: driver selection for different writer types
Y stands for yes and means you should put the beast into the kernel. M stands for module and means you
should or must compile this feature as a module. Y/M gives you the option to decide between either (order
indicates choices with less potential problems). Empty settings don't need to be modified and not changing
them increases the chance that the resulting kernel will work for you (if it did before...). Especially in
environments where SCSI and ATAPI devices are mixed, you better build most things as modules.
Compiling loopback device is optional. It allows you to test the image before writing it to the media. If you
want to be able to read CD−ROMs, you need support for the ISO 9660 filesystem. This driver automatically
includes RockRidge Extensions. The Microsoft Joliet CD−ROM extensions have to be explicitly added to the
ISO 9660 filesystem. In any case, you need a low−level driver for your hardware. Low−level refers to the
driver, which interacts directly with the hardware. For SCSI and the parallel port, there are a lot of low−level
drivers available.
Installing the resulting Linux−kernel is beyond the scope of this HOWTO. Please consult the documentation
of your Linux−distribution.
Users of RedHat Linux be aware that you have to compile in the features "Ramdisk support" and "Initial
ramdisk". Furthermore, you have to generate a new ramdisk with the new modules by issuing a command
like "mkintrd −−preload ide−cd initrd−2.2.14.img 2.2.14".
2.2 Get the user software for burning CD−Rs
A more detailed survey of tools related to produce CD−ROMs is available from
http://www.fokus.gmd.de/research/cc/glone/employees/joerg.schilling/private/cdb.html.
Command line utilities
One of the following packages are required to generate images of CD−Rs (only required for data
CD−ROMs):
ftp://tsx−11.mit.edu/pub/linux/packages/mkisofs/ (mkisofs)
2.2 Get the user software for burning CD−Rs
13
CD−Writing HOWTO
ftp://ftp.ge.ucl.ac.uk/pub/mkhfs (mkhybrid)
To write images to the CD−R, you need one of the following software packages:
ftp://ftp.fokus.gmd.de/pub/unix/cdrecord/ (cdrecord)
http://www.ping.de/sites/daneb/cdrdao.html (cdrdao)
http://www.munich−vision.de/vcd/ (mkvcdfs)
Don't trust the man page of old versions of mkisofs which state you need version 1.5 of cdwrite. Just
use cdrecord and you are fine. Please note that newer versions of cdrecord ship with an enhanced version of
mkisofs and some extra tools in the subdirectory misc/ (readcd, isosize) not found elsewhere.
Graphical user interfaces (optional)
Front−ends are really front−ends under Linux. That means, you still have to install the command−line
utilities, but you access them in a better looking manner.
X−CD−Roast is a program package dedicated to easy CD creation under Linux. It combines command line
tools like cdrecord and mkisofs into a nice graphical user interface.
http://www.fh−muenchen.de/home/ze/rz/services/projects/xcdroast/e_overview.html
BurnIT is a JAVA front−end to cdrecord, mkisofs and cdda2wav−0.95 making it a complete package for
burning CDs on the Unix platform. It is available from
http://sunsite.auc.dk/BurnIT/
CD−Tux is a character based frontend for the programs mkisofs and cdrecord. "It creates an easy to use
enviroment for doing almost anything to a CD in full color through the use of the (in)famous NCURSES
Library. And it does all this whith an executable of under 75K."
http://www.datadictator.co.za/cdtux/
Graphical user interfaces (optional)
14
CD−Writing HOWTO
3.Burning CD−Rs
"If to smoke you turn I shall not cease to fiddle while you burn." (Roman emperor Nero about
burning his own classic−CDs, AD64. He misunderstood it completely and burned Rome
down.)
Writing CD−ROMs consists of two steps under Linux:
• packaging the desired data (files, music or both) into files with special formats
• writing the data from the files to the CD−R with the utility cdrecord
This chapter describes the steps for data and audio CDs in greater detail.
3.1 Writing CD−ROMs (pure data)
Note that collecting the data to put onto a CD usually takes longer than one expects. Consider that missing
files cannot be added once the CD is written and fixated. This is also true for CD−RW, which can currently
only be rewritten as a whole. Using the multi−session feature is no option for single files, as it consumes
much space for a new complete table of contents (TOC). UDF is not ready yet for Linux.
Also keep in mind that a certain amount of the free space of a CD is used for storing the information of the
ISO−9660−filesystem (usually a few MB). 620 MB data will always fit on a 650 MB CD−R.
Creating an image of the later CD−ROM
Before any storage medium (e.g. floppy disk, hard disk or CD) can be used, it must get a filesystem (DOS
speak: get formatted). The filesystem is responsible for organizing and incorporating the files that should be
stored on the medium.
The usual utilities for creating filesystems on hard disk partitions write an empty filesystem onto them, which
is then mounted and filled with files by the users as they need it. A writable CD is only writable once so if we
wrote an empty filesystem to it, it would get formatted and remain completely empty forever. This is also true
for rewritable media as you cannot change arbitrary sectors yet; you must erase their whole content.
So what we need is a tool that creates the filesystem while copying the files to the CD. This tool is called
mkisofs. A sample usage looks as follows:
mkisofs
−r
3.Burning CD−Rs
−o cd_image
`−−−−−−−−−'
|
private_collection/
`−−−−−−−−−−−−−−−−−'
|
15
CD−Writing HOWTO
write output to
take directory as input
The option '−r' sets the permissions of all files to be public readable on the CD and enables
RockRidge−extensions. You probably want to use this option unless you really know what you're doing (hint:
without '−r' the mount point gets the permissions of private_collection!).
mkisofs will try to map all filenames to the 8.3 format used by DOS to ensure the highest possible
compatibility. In case of naming conflicts (different files have the same 8.3 name), numbers are used in the
filenames and information about the chosen filename is printed via STDERR (usually the screen). Don't
panic: Under Linux you will never see these odd 8.3 filenames because Linux makes use of the Rock Ridge
extensions which contain the original file information (permissions, filename, etc.).
Remeber do use the Option −J (MS Joliet extensions) or use mkhybrid if you want to generate a more
Windows−friendly CD−ROM. For HFS CD−ROMS used on the Macintosh, you better read the man−page of
mkisofs' bigger sister mkhybrid for details on various options.
Now you may wonder why the output of mkisofs is not directly sent to the writer device. There are three
reasons:
• mkisofs knows nothing about driving CD−writers.
• You may want to test the image before burning it.
• On slow machines it would not be reliable (see section 4.).
There is a method to write a CD−R in one go, which will be described below.
One also could think of creating an extra partition and writing the image to that partition instead to a file. I
vote against such a strategy because if you write to the wrong partition due to a typo, you can lose your
complete Linux system. Read: that happened to me... Furthermore, it is a waste of disk space because the
CD−image is temporary data that can be deleted after writing the CD. However, using raw partitions saves
you the time for deleting files of 650 MB size.
Test the CD−image
Linux has the ability to mount files as if they were disk partitions. This feature is useful to check that the
directory layout and file access permissions of the CD image matches your wishes. Although media is very
cheap today, the writing process is still time consuming, and you may at least want to save your time by
doing a quick test.
To mount the file cd_image created above on the directory /cdrom, give the command
mount −t iso9660 −o ro,loop=/dev/loop0 cd_image /cdrom
Now you can inspect the files under /cdrom −− they appear exactly as they were on a real CD. To umount
the CD−image, just say umount /cdrom. (Warning: On Linux kernels prior to 2.0.31 the last file on
Test the CD−image
16
CD−Writing HOWTO
/cdrom may not be fully readable. Please use a more recent kernel like 2.0.36. The option −pad for cdrecord
applies to audio CDs only and the option −pad for mkisofs requires a patch, which is as much work to apply
than to upgrade to a bug−free Linux kernel.)
Note:
Some ancient versions of mount are not able to deal with loopback devices. If you have
such an old version of mount, then upgrade your Linux−system. Several people have
already suggested putting information about how to get the newest mount utilities into this
HOWTO. I always refuse this. If your Linux distribution ships with an ancient mount,
report it as a bug. If your Linux distribution is not easily upgradable, report it as a bug.
If I include all the information that is necessary to work around bugs in badly designed Linux
distributions, this HOWTO would be a lot bigger and harder to read.
Write the CD−image to a CD
This section only covers writing data CDs in TAO mode, because it is the most frequently used mode for
data. For more information about the differences of TAO and DAO, please see the chapter about audio
CD−Rs. If you use DAO mode with the tool cdrdao, then remember to add a dummy audio track at the end of
the TOC file (see the README).
Not much more left to do. If you haven't already tried, it's a good time for the command
cdrecord −scanbus
This will tell you to which SCSI device your CD−writer is attached to. All other methods of guessing the
information printed so nicely by cdrecord have been removed from the HOWTO.
Before showing you the last command, let me warn you that CD−writers want to be fed with a constant
stream of data. So the process of writing the CD image to the CD must not be interrupted or a corrupt CD
will result. It's easy to interrupt the data stream by deleting a very large file. Example: if you delete an old
CD−image of 650 Mbytes size, the kernel must update information about 650,000 blocks on the hard disk
(assuming you have a block size of 1 Kbyte for your filesystem). That takes some time and is very likely to
slow down disk activity long enough for the data stream to pause for a few seconds. However, reading mail,
browsing the web, or even compiling a kernel generally will not affect the writing process on modern
machines.
Please note that no writer can re−position its laser and continue at the original spot on the CD when it gets
disturbed. Therefore any strong vibrations or other mechanical shocks will probably destroy the CD you are
writing.
When you are mentally prepared, dress up in a black robe, multiply the SCSI−id of the CD−writer with its
SCSI−revision and light as many candles, speak two verses of the ASR−FAQ (newsgroup
alt.sysadmin.recovery) and finally type:
Write the CD−image to a CD
17
CD−Writing HOWTO
shell>
shell>
shell>
shell>
SCSI_BUS=0
# taken from listing 1 "scsibus0:"
SCSI_ID=6
# taken from listing 1 "TOSHIBA XM−3401"
SCSI_LUN=0
cdrecord −v speed=2 dev=$SCSI_BUS,$SCSI_ID,$SCSI_LUN \
−data cd_image
# same as above, but shorter:
shell> cdrecord −v speed=2 dev=0,6,0
−data
cd_image
For better readability, the coordinates of the writer are stored in three environment variables with natural
names: SCSI_BUS, SCSI_ID, SCSI_LUN.
If you use cdrecord to overwrite a CD−RW, you must add the option "blank=..." to erase the old content.
Please read the man page to learn more about the various methods to blank the CD−RW.
In times where everybody except me owns a 400 Mhz machine, people feed the output of mkisofs directly
into cdrecord:
shell> IMG_SIZE=`mkisofs −R −q −print−size private_collection/ 2>&1 \
| sed −e "s/.* = //"`
shell> echo $IMG_SIZE
shell> [ "0$IMG_SIZE" −ne 0 ] && mkisofs −r private_collection/ \
|cdrecord speed=2 dev=0,6,0
tsize=${IMG_SIZE}s −data −
#
don't forget the s −−^
^−− read data from STDIN
The first command is an empty run to determine the size of the image (you need the mkisofs from the
cdrecord distribution for this to work). You need to specify all parameters you will use on the final run (e.g.
−J or −hfs). Maybe your writer does not need to know the size of the image to be written, so you can leave
this dry run out. The printed size must be passed as a tsize−parameter to cdrecord (it is stored in the
environment variable IMG_SIZE). The second command is a sequence of mkisofs and cdrecord, coupled via
a pipe.
The
3.2 Writing audio CDs
Writing audio CDs is very similar to the steps described above for data CDs. You can choose between two
techniques: DAO or TAO. TAO (track at once) is less suitable for music, because you will hear clicks
between the individual tracks. It is described first anyways, because it is a little bit easier to deal with and
DAO is not available for all drives yet.
The main difference compared to writing data CD−Rs is the format of the images. ISO−9660 (or whatever
filesystem you prefer) would not be suitable, because no audio CD player is able to deal with filesystems.
Instead the audio data must be writen as "16 bit stereo samples in PCM coding at 44100 samples/second
(44.1 kHz)".
One utility to convert your sound files into the required format is sox. Its usage is straightforward:
3.2 Writing audio CDs
18
CD−Writing HOWTO
shell> sox
killing−my−software.wav
killing−my−software.cdr
This command would convert the song killing−my−software from the WAV−format into the CDR
audio−format. See the man page for sox for more details about formats and filename−extensions sox
recognizes. Because the output of the manual conversion takes up much disk space, it was made a built−in
feature of cdrecord for the sound formats WAV and AU. So as long as your sound files have the extensions
.wav or .au (and the sample rate "stereo, 16 bit, 44.1 kHz"), you can use them as audio tracks without manual
conversion into the CDR format. However, cdrecord requires the size of the sound data to be a integer
multiple of 2352 and to be greater than 705,600 bytes, which is not fullfilled for some WAV files. For such
files the usage of sox is needed to pad the audio data up to 2352 bytes.
Writing audio CDs (TAO)
An audio CD consists of audio tracks, which are organized as separate images when using TAO mode. So if
you want to have ten tracks on your CD, you have to make ten images.
Cdrecord writes CD images as audio tracks if the option −audio is specified. The other options are identical
to those used for writing data−CDs (unless you have very special requirements). These three examples all do
the same thing, but read the tracks from different sound file formats:
shell> cdrecord −v speed=2 dev=0,6,0
shell> cdrecord −v speed=2 dev=0,6,0
shell> cdrecord −v speed=2 dev=0,6,0
−audio
−audio
−audio
track1.cdr track2.cdr...
track1.wav track2.wav...
track1.au track2.au...
By doing this, you will produce an audio CD which has a 2 seconds of pause between audio tracks. One
notable format not directly readable by cdrecord is MPEG Layer 3. To convert files in this format to the
CDR−format, you can use the command "mpg123 −−cdr − track1.mp3 > track1.cdr". The option −−cdr
ensures the track is encoded in the required format (see above). Older versions of mpg123 require −s instead
of the plain − to write to stdout. The other direction (converting from WAV to MPEG) can be done with
LAME for WAV−files (extract the track with cdda2wav from the audio CD and encode it into MP3 with the
help of LAME).
To create a CD−R from a whole bunch of MP3−files, you can use the following command sequence:
for I in *.mp3
do
mpg123 −−cdr − "$I" | cdrecord −audio −pad −nofix −
done
cdrecord −fix
Depending on the speed of your machine, you may want to slow down writing to "speed=1" (cdrecord
option). If you use "speed=4", your machine must be able to play the MP3−file at quadruple speed. mpg123
consumes much CPU−time! If you are in doubt, try an empty run with −dummy (keeps the laser switched
Writing audio CDs (TAO)
19
CD−Writing HOWTO
off).
DAO
If you want to get rid of the pauses between the audio tracks, you have to use disk−at−once (DAO) recording
versus the (individual) track−at−once (TAO) recording described above. Support for DAO is currently most
advanced in cdrdao. Please see its homepage for details.
If you master the CD in DAO mode, then you use a monolithic image (sound file) and control track
information with a configuration file.
CD_DA
TRACK AUDIO
FILE "live.wav" 0 5:0:0
INDEX 3:0:0
TRACK AUDIO
FILE "live.wav" 5:0:0 5:0:0
TRACK AUDIO
FILE "live.wav" 10:0:0 5:0:0
INDEX 2:0:0
3.3 Mixed mode CD−ROMs
There is not much to say about this topic. Just indicate the type of the (subse quent) images with the options
−data and −audio. Example:
cdrecord
−v dev=0,6,0
−data
cd_image
−audio
track*.cdr
4.Dear Winfried,...
This is the section usually known as "frequently asked questions with answers". If you have a problem with
your partner, kids or dog, just send it in, as long as it is related to writing CD−Rs or is otherwise entertaining.
DAO
20
CD−Writing HOWTO
4.1 How sensitive is the burning process?
Test it. Use the option −dummy to do an empty run of cdrecord. Do everything you would do otherwise and
watch if the burning process survives.
If you feed cdrecord directly from mkisofs, then disk intensive processes such as updating the locate database
lower the maximum flow rate and may corrupt the CD. You better check such processes are not started via
cron, at or anacron while you burn CD−Rs on older machines.
4.2 Has file fragmentation a bad impact on the throughput?
Fragmentation of files is usually so low that its impact isn't noticed. However, you can easily construct
pathological cases of fragmentation, which lower the throughput of your hard disks under 100 kbytes/second.
So don't do that. :−) Yes, files on a hard disk get fragmented over the years. The faster, the fuller the
filesystem is. Always leave 10% or 20% free space, and you should run fine with respect to writing CD−Rs.
If you're uncertain then look at the messages printed while booting. The percentage of fragmentation is
reported while checking the filesystems. You can check for this value with the very dangerous command
shell> e2fsck −n /dev/sda5
# '−n' is important!
[stuff deleted −− ignore any errors]
/dev/sda5: 73/12288 files (12.3% non−contiguous)
In this example the fragmentation seems to be very high −− but there are only 73 very small files on the
filesystem. So the value is not alarming.
There is an experimental utility called e2defrag to defragment extended−2 filesystems. The current version
does not work reliable enough to use it even for private environments. If you really want to defragment your
filesystem, make a backup copy (better: two copies), practice restoring the data, then create a new filesystem
(that will destroy the old) and restore the data. This sketch is currently the safest technique.
4.3 Is it possible to store the CD−image on an
UMSDOS−filesystem?
Yes. The only filesystem that isn't reliable and fast enough for writing CD−ROMs from is the network
filesystem (NFS). I used UMSDOS myself to share the disk−space between Linux and DOS/Win on a PC
(486/66) dedicated for writing CD−ROMs.
4.1 How sensitive is the burning process?
21
CD−Writing HOWTO
4.4 Isn't there some way to get around the ISO−9660
limitations?
Yes. You can put any filesystem you like on the CD. But other operating systems than Linux won't be able to
deal with this CD. Here goes the recipe:
• Create an empty file of 650MB size.
dd if=/dev/zero of="empty_file" bs=1024k count=650
• Create an extended−2 filesystem on this file
shell> /sbin/mke2fs −b 2048 empty_file
empty_file is not a block special device.
Proceed anyway? (y,n) y
• Mount this empty file through the loopback devices (you need a reasonable new mount for this; read
above).
mount −t ext2 −o loop=/dev/loop1 empty_file /mnt
• Copy files to /mnt and umount it afterwards.
• Use cdrecord on empty_file (which is no longer empty) as if it were an ISO−9660−image.
If you want to make an entry in /etc/fstab for such a CD, then disable the checking of the device file on
system startup. For example:
/dev/cdrom
/cdrom
ext2
defaults,ro
0 0
The first 0 means "don't include in dumps" (backup), the second (=important) one means "don't check for
errors on startup" (fsck would fail to check the CD for errors).
4.5 How to read the tracks from audio CDs?
There are several software packages available. The newest one is "cdpranoia" and can be downloaded from
http://www.xiph.org/paranoia/
4.4 Isn't there some way to get around the ISO−9660 limitations?
22
CD−Writing HOWTO
Or you want to try the combination of "cdda2wav" and "sox", available from sunsite and its mirrors:
ftp://sunsite.unc.edu/pub/Linux/apps/sound/cdrom/cdda2wav0.71.src.tar.gz
ftp://sunsite.unc.edu/pub/Linux/apps/sound/convert/sox−11gamma−cb3.tar.gz
cdda2wav enables you to get a specific interval (or a whole track) from your audio CD and converts it into
a .wav−file. sox converts the WAV files back into the (audio CD) cdda−format so it can be written to the
CD−R using cdrecord. You don't necessarily need sox if you use a recent version of cdrecord, because
it has built−in support for .au and .wav files.
4.6 How to probe for SCSI devices after boot?
The file drivers/scsi/scsi.c contains the information
/*
* Usage: echo "scsi add−single−device 0 1 2 3" >/proc/scsi/scsi
* with "0 1 2 3" replaced by your "Host Channel Id Lun".
* Consider this feature BETA.
*
CAUTION: This is not for hot plugging your peripherals. As
*
SCSI was not designed for this you could damage your
*
hardware !
* However perhaps it is legal to switch on an
* already connected device. It is perhaps not
* guaranteed this device doesn't corrupt an ongoing data transfer.
*/
Please note that this should only be used if your add SCSI devices to the end of the chain. Inserting new SCSI
devices into an existing chain disturbs the naming of devices (directory /dev) and may destroy the complete
content of your hard disk.
Some kernel versions do not like re−scanning the SCSI bus at all and your system may freeze solid when
trying out the above. You have been warned.
4.7 Is it possible to make a 1:1 copy of a data CD?
Yes. But you should be aware of the fact that any errors while reading the original (due to dust or scratches)
will result in a defective copy. Please note that both methods will fail on audio CDs! You have to use cdrdao
or cdda2wav on audio CDs.
4.6 How to probe for SCSI devices after boot?
23
CD−Writing HOWTO
First case: you have a CD−writer and a separate CD−ROM drive. By issuing the command
cdrecord −v dev=0,6,0 speed=2 −isosize /dev/scd0
you read the data stream from the CD−ROM drive attached as /dev/scd0 and write it directly to the
CD−writer.
Second case: you don't have a separate CD−ROM drive. In this case you have to use the CD−writer to read
out the CD−ROM first:
dd if=/dev/scd0 of=cdimage
This command reads the content of the CD−ROM from the device /dev/scd0 and writes it into the file
"cdimage". The contents of this file are equivalent to what mkisofs produces, so you can proceed as
described earlier in this document (which is to take the file cdimage as input for cdrecord). If you want to see
a progress−meter and other fancy stuff, then you can also use Jörg Schillings sdd.
In case you run into errors, then install a recent version of cdrecord, which ships a tool called "readcd" (found
under misc/). It gives you the same result as dd, but reads sectors on the CD−ROM several times in case of
errors.
4.8 Can Linux read Joliet CD−ROMs? (obsolete answer)
Yes. Newer Kernels (2.0.36 and the upcoming 2.2) have built−in support for the joliet format. Remember you
have to use both options in your /etc/fstab: the keywords iso9660 and joliet (later is really an extension). For
more details, see http://www−plateau.cs.berkeley.edu/people/chaffee/joliet.html.
4.9 How do I read/mount CD−ROMs with the CD−writer?
Just as you do with regular CD−ROM drives. No tricks at all. Note that you have to use the scd devices
(SCSI CD−ROM) to mount CD−ROMs for reading, even if you have an ATAPI CD−ROM (remember you
configured your ATAPI devices to act like SCSI). Example entry for /etc/fstab:
/dev/scd0
/cdrom
iso9660
ro,user,noauto
0
4.8 Can Linux read Joliet CD−ROMs? (obsolete answer)
0
24
CD−Writing HOWTO
4.10 How to put even more data on the CD−R?
Use bzip2 instead of any other compressor like gzip or pkzip. It will save you up to 30% of disk−space
for larger (>100kb) files. You can download it from
http://www.muraroa.demon.co.uk/
Instead of writing a true audio CD, you can optionally convert your WAV audio files into MP3 audio files
and store them on a ISO−9660 filesystem as regular files. Usually MPEG III give you a compression of 1:10.
Of course, most CD−players are not able to read files... this is the drawback. On the other hand, why not
running the music for your next party from hard disk? 18 Gbytes are enough for 3000−4000 titles. :−)
A software MPEG III−encoder is available from
http://www.sulaco.org/mp3/
A MPEG III−player is available from
http://www.mpg123.org/
For recorded speech, you may want to try to reduce its size using shorten or "GSM lossy speech
compression":
ftp://svr−ftp.eng.cam.ac.uk/pub/comp.speech/
http://kbs.cs.tu−berlin.de/~jutta/toast.html
4.11 How to make bootable CD−ROMs?
You must have an 1.44 MB bootable floppy−disk. Create an exact image of this floppy−disk by issuing the
command
dd if=/dev/fd0 of=boot.img bs=18k
4.10 How to put even more data on the CD−R?
25
CD−Writing HOWTO
Place this floppy image into the directory holding the collection of your files (or into a subdirectory of it, just
as you like). Tell mkisofs about this file with the option '−b' and also use '−c'. For details read the file
README.eltorito in the mkisofs−distribution.
An interesting application for a custom bootable CD is as a virus safe DOS− or Windows−system. It saves
you the money for the hard disks (if you have a network and use samba to put the user−data on a file server).
The German computer magazine c't has a article about this issue in the issue 11/99, page 206 (
http://www.heise.de/).
Some details about the bootable RedHat CD−ROM is available from
http://members.bellatlantic.net/~smithrod/rhjol−technical.html.
4.12 How to make CD−ROMs writable like a hard disk?
There is an overlay filesystem available for Linux, which is mounted over the CD−ROM and intercepts all
writing operations. New and modified files are stored elsewhere, but for the user it looks like the CD−ROM
is modified. For more information, see http://home.att.net/~artnaseef/ovlfs/ovlfs.html.
If that is not enough for your needs: wait for the UDF−filesystem to be supported by Linux or help
developing it (see http://trylinux.com/projects/udf/. At the moment only reading of CD−media is supported
due to a limitation in the CD−ROM drivers of the Linux kernel.
4.13 Is it possible to use several writers at once?
Yes. It is reported to work with at least 3 writers at full speed (6x) on a PC with 233 Mhz and a single SCSI
bus running kernel 2.2.12. You need either a recent version of the Linux kernel (2.2.12 or higher).
4.14 What about Solaris, *BSD, AIX, HP−UX, etc.? Is my
variant of Unix supported?
Only chapter 2 is Linux−specific. You can apply chapter 3 and 4 even if you run another family of operating
systems than Linux. Please see the files README.NetBSD, README.aix, README.hpux,
README.next, README.solaris, README.sunos, README.vms or README.xxxBSD from the
cdrecord−distribution.
Probably yes. Compile cdrecord for your platform and issue the command "cdrecord −scanbus". Read the
README.* file for your Unix distributed with the sources of cdrecord. However, not all variants of Unix can
read the RockRidge, Joliet or HFS extensions on your newly written CD−R.
4.12 How to make CD−ROMs writable like a hard disk?
26
CD−Writing HOWTO
4.15 Where to store the local configuration permanently?
You have two options. Either you use the built−in configuration file for cdrecord, or you use a shell wrapper
like the one shown below. This shell script reads a configuration file, which lists the options and parameters
for cdrecord line by line. The names are exactly the same as on the command line, but without the leading
dash. Comments are allowed. Example:
# be verbose
v
# set the speed of the writer
speed=2
# the device−coordinates in the form BUS,ID,LUN
dev=0,6,0
The configuration files for the wrapper belong into /etc/cdrecord/ and must be referenced on the command
line. Example: if you want to refer to the configuration /etc/cdrecord/mywriter.cfg, then you can issue the
command "cdrecord.sh mywriter.cfg −audio track1...". Everything after mywrite.cfg is passed to cdrecord.
#! /bin/bash
CFGDIR="/etc/cdrecord"
CFG="$1"
shift
ARGS_LEFT="$@"
if [ ! −f "$CFGDIR/$CFG" ]
then
echo "Configuration file $CFGDIR/$CFG not found. Exiting."
exit 1
fi
while read LINE
do
case $LINE in
\#*|"") continue;;
esac
old_IFS="$IFS"
IFS="$IFS="
set −− $LINE
IFS="$old_IFS"
O_NAME="$1"
O_VALUE=""
while shift
do
case $1 in
"") continue;;
esac
O_VALUE="$1"
done
if [ −z "$O_VALUE" ]
4.15 Where to store the local configuration permanently?
27
CD−Writing HOWTO
then
O_CDRECORD="$O_CDRECORD −$O_NAME "
continue
fi
O_CDRECORD="$O_CDRECORD $O_NAME=$O_VALUE "
done < "$CFGDIR/$CFG"
set −x
#DEBUG
exec cdrecord $O_CDRECORD $ARGS_LEFT
echo "Execution of cdrecord failed."
4.16 How can the CD−info be retrieved?
Somewhere behind the first 32 k on the CD, a block with information about the CD is located. You can
extract the information with the following shell script:
#! /bin/bash
RD=/dev/cdrom
for i in 32768,7
32776,32 32808,32 32958,128 33086,128 33214,128 \
33342,128 33470,32 33581,16 33598,16 33615,16 33632,16
do
old_IFS="$IFS"
IFS=","
set −− $i
IFS="$old_IFS"
OFFSET=$1
LENGTH=$2
echo "*`dd if=$RD bs=1 skip=$OFFSET count=$LENGTH
2> /dev/null`#"
done
4.17 What about re−writing
When overwriting CD−RW media, specify the parameter blank=fast to cdrecord. That's all. See the man page
of cdrecord for details about this parameter.
4.18 How to create a multi−session CD?
First of all, the image for a multi−session CD must be formatted using the ISO−9660 filesystem using
RockRidge−extensions. And you must use the option −multi for cdrecord as long as you want to add further
sessions. So at least for the first session, you must specify the option −multi.
Some CD−writers have no support for CD−ROM XA mode 2 or for session−at−once (SAO), so you need to
4.16 How can the CD−info be retrieved?
28
CD−Writing HOWTO
specify the switch −data for cdrecord on the command line.
The images for the second and subsequent sessions are a little bit more complicated to generate. Mkisofs
must know where the free space on the CD−R begins. That information can be gathered by using the option
−msinfo on cdrecord (see example below).
shell> NEXT_TRACK=`cdrecord −msinfo dev=0,6,0`
shell> echo $NEXT_TRACK
shell> mkisofs −R −o cd_image2 −C $NEXT_TRACK −M /dev/scd5
private_collection/ \
For more information, please read the file README.multi, which is distributed with cdrecord.
4.19 Should I use the SCSI adapter shipped with the writer?
Reported via email: Most CD−writer docs say to use a separate SCSI bus if going from a CD−ROM to a
CD−writer and I have seen this myself in the following scenario:
Adaptec 2940UW SCSI card, a 24x SCSI CD−ROM and a 4x4 SCSI CD−writer. When I got the CD−writer,
it came with its own ISA SCSI card which could only handle one device. I figured I'd toss this and use my
better adaptec card for all the stuff. I noticed it was quite prone to buffer under−runs when recording at the 4x
speed, but as soon as I tried hooking up the ISA SCSI card, it had no problems. I know 2 other people (both
using adaptec 2940 cards), who have experienced exactely the same symptoms, usually when writing from a
CD−ROM to a CD−recorder. Though I've never experienced the problem when going from a hard drive to a
CD−writer on the same bus.
4.20 How to burn over the network?
Usally a file transfer with FTP is fast enough to feed a CD−recorder at quadruple (4x) speed even over a 10
Mbit ethernet. You can couple the ftp−client and cdrecord via a fifo. First create a fifo named cdimage:
mkfifo cdimage
ftp other.host.org
get cdimg cdimage
Then treat cdimage like a regular file, i.e. issue the following command:
cdrecord dev=0,1,0 speed=2 cdimage
4.19 Should I use the SCSI adapter shipped with the writer?
29
CD−Writing HOWTO
Your ftp−client will notice when cdrecord wants to read from the file and will start transfering data from the
ftp−host.
4.21 I hear a crack or click sound at the end of the each
track.
You have to use disk−at−once mode (DAO) to get rid of the cracks.
4.22 How can this be set up so that a user can burn CDs
instead of always being root?
You can add the setuid−bit to the cdrecord−executable. However, this might be a security risk. Just setting
the permissions on the device files does not help as cdrecord issues privileged commands via the SCSI
generic interfaces.
which cdrecord
chown root.root /usr/bin/cdrecord
chmod 4111 /usr/bin/cdrecord
4.23 Where do I get the "Yellow Book" and "Orange Book"
standards?
You get the printed specifications from Philips and they are expensive.
4.24 I've been searching for information on burning
Video−CD under Linux.
Here you can find utilities for creation of MPEG videos and Video−CDs: http://www.mainconcept.de/
http://www.johanni.de/munich−vision/vcd/
Political correct people mention the Berkeley−tools and other YUV−strategies. Their usage is complicated,
takes much time and harddisk−space and gives you no audio track. I recommend to use conceptually higher
4.21 I hear a crack or click sound at the end of the each track.
30
CD−Writing HOWTO
level applications like the ones mentioned above.
4.25 Which is easier to set up, IDE or SCSI?
SCSI CD−writers are slightly easier to set up with regard to CD−writing under Linux. And they are reported
to have better error recovery. If that outweights the higher price cannot be answered generally.
4.26 How can I overburn a CD using {cdrecord,cdrdao}?
Overburning a CD−R is nothing special. It is at your own risk that the data fits on the CD−ROM, but thats all.
There are no 650 Mbytes−limits in the software under Linux.
4.27 What will cdrecord do when it stops getting input from
the pipe?
It will finish writing. So you can just couple your favourite backup tool with cdrecord using a pipe, like in
"bru −size=640m −f − | cdrecord dev=0,1,0 speed=2 −". You have to take special care within the backup
utility if the backup spans multiple CD−Rs.
4.28 Is there an equivalent to ignore=hdX for the ide−scsi
emulation?
I know of no way, but anybody is welcome to add this feature to the Linux kernel sources.
4.29 How many times can you re−use CD−RW before they
become faulty?
Good question.
4.25 Which is easier to set up, IDE or SCSI?
31
CD−Writing HOWTO
4.30 Which format to choose for a platform independant
CD−ROM?
A CD−ROM to be read by all systems can only use the plain ISO 9660 format. That means stupid 8+3
filenames from old MS−DOS and without any HFS (Macintosh), Joliet (Microsoft) or RockRidge (newer
Unices) extensions. There is no extension for longer filenames, which could be read by all operating systems.
4.31 Is multi−session for audio tracks possible?
Audio CD−players are only able to deal with audio tracks stored in the first session. In other words, you
cannot add audio tracks using subsequent sessions. However, writing data tracks into the second session
effectively hides them from audio CD−players. This way you prevent having an silent track on your mixed
mode CD (audio and data mixed).
4.32 What hardware resources do I need? Is an old Pentium
enough?
An answer depends on your wishes. If you need a reason to buy a new computer, here is the answer from the
international association of computer manufactures: Whatever you plan to do, you need a processor with 800
Mhz. Because it won't fit into your existing motherboard, you need a new motherboard, too. The easiest
solution is just to buy the typical complete offer as seen in advertisements on TV. Please ignore the rest of
this section.
Now the case if you just want a rational answer: I wrote several CD−ROMs sucessfully using a "486" with 66
Mhz. Although MS does not consider them to be PCs anymore, but recommends to run a CE version on them
(seen on the CeBIT), Linux runs even fine on the predecessors of the Pentium and is even able to write CDs.
You can easily find out if the power of your hardware is sufficient for writing CD−ROMs by testing it out.
Just add the command line switch −dummy when executing cdrecord and the laser will be kept off. Watch the
burning process.
5.Troubleshooting
Always remember, that you can still use corrupt CD−ROMs as coasters. :−)
4.30 Which format to choose for a platform independant CD−ROM?
32
CD−Writing HOWTO
5.1 It doesn't work: under Linux
Please check first, that the writer works under the software it is shipped with (=under another operating
system). Concretely:
• Does the controller recognize the writer as a SCSI device?
• Does the driver software recognize the writer?
• Is it possible to make a CD using the accompanied software?
If "it doesn't even work" with the accompanied software you have a hardware conflict or defective hardware.
If it works and you use loadlin to boot Linux, then that is a problem with loadlin. Loadlin makes a
warm−boot with most of the hardware already initialized and that can confuse the Linux kernel.
5.2 Error−message: No read access for 'dev=0,6,0'.
Under Linux, some versions of the C−library are incompatible (buggy), so that an application linked against
one version will not work with another. An example for an error triggered by pre−compiled binaries is the
following:
[root@Blue /dev]# cdrecord −eject dev=0,6,0
cdrecord: No such file or directory. No read access for 'dev=0,6,0'.
The solution is to install a newer C−library.
5.3 It doesn't work: under DOS and friends
Try to use Linux. Installation and configuration of SCSI drivers for DOS is the hell. Linux is too
complicated? Ha!
5.4 SCSI errors during the burning phase
Most likely those errors are caused by
• missing dis−/reconnect feature on the SCSI bus
• insufficiently cooled hardware
• defective hardware (should be detected by 5.1.)
5.1 It doesn't work: under Linux
33
CD−Writing HOWTO
Under various circumstances SCSI devices dis− and reconnect themselves (electronically) from the SCSI bus.
If this feature is not available (check controller and kernel parameters) some writers run into trouble during
burning or fixating the CD−R.
Especially the NCR 53c7,8xx SCSI driver has the feature disabled by default, so you might want to check it
first:
NCR53c7,8xx SCSI support
[N/y/m/?] y
always negotiate synchronous transfers [N/y/?] (NEW) n
allow FAST−SCSI [10MHz]
[N/y/?] (NEW) y
allow DISCONNECT
[N/y/?] (NEW) y
5.5 Medium errors If cdrecord reports medium errors in the
form of"Sense Key: ... Medium Error, Segment ...", then the
mediumis not empty. If you use CD−RW, then try to switch
fromblank=fast to the more reliable blank=all. If you use
CD−Ronly, then make sure the CD−R has never seen a
CD−writer beforeor try out discs from another
manufacturer.
5.6 Newly written CDs are not readable on some players.
Some people reported problems with playing their self−written CDs. Very old audio players or car devices
can have problems with CD−Rs, although this is extremly rare. Quite frequent are problems with CD−RWs,
because they don't reflect the laserlight as good as CD−Rs and factory−pressed "silver" discs.
5.7 My scanner stopped working after I loaded the ide−scsi
module
By inserting the SCSI−hostadaptor emulation, the naming of SCSI devices changes. If your scanner was
/dev/sg0 before, it might be /dev/sg1 or /dev/sg2 now. Prominent kernel developers did not think this is
completely braindead and denied solutions like devfs in the past. But that is another story, the first thing you
should try is to set the link /dev/scanner to point to the actual generic SCSI device. Examples:
5.5 Medium errors If cdrecord reports medium errors in the form of"Sense Key: ... Medium Error, Segment
34
..
CD−Writing HOWTO
cd /dev
ls −l scanner
# shows current setting
ln −sf sg2 scanner
# test the scanner
ln −sf sg1 scanner
# test the scanner
# and so on
Application developers should carefully think about support for this dangerous and error prone naming
scheme. Please consider at least to use intermediate solutions like the SCSI coordinates used by cdrecord.
6.Credits
Many thanks go to the readers of this HOWTO, who contributed actively to its contents. As I don't had access
to a CD−writer myself for several years, reports about real live setups and experience have always been of
great value to me.
Doug Alcorn <doug@lathi.net>
helped to improve the handling of newer kernels
Kalle Andersson <kalle@sslug.dk>
How to write audio CDs directly from MP3.
Alan Brown <alan@manawatu.net.nz>
Rick Cochran <rick@msc.cornell.edu>
hint about dis−/reconnect disabled by default in the ncr driver
Robert Doolittle <bob.doolittle@sun.com>
good arguments for dropping cdwrite from the HOWTO
Markus Dickebohm <m.dickebohm@uni−koeln.de>
Thomas Duffy <tduffy@sgi.com>
major cleanup of syntax and spelling
Dave Forrest <dforrest@virginia.edu>
6.Credits
35
CD−Writing HOWTO
fixed adapter spelling problems
Jos van Geffen <jos@tnj.phys.tue.nl>
noted the problem in 4.9.
Bernhard Gubanka <beg@ipp−garching.mpg.de>
noticed the need of a recent version of mount to utilize the loopback device
Stephen Harris <sweh@mpn.com>
contributed hint about writing audio CDs
Janne Himanka <shem@oyt.oulu.fi>
pointer to kernel patch to read Joliet CD−ROMs
Stephan Noy <stnoy@mi.uni−koeln.de>
information and experience about writing audio CDs
Don H. Olive <don@andromeda.campbellsvil.edu>
URL of the mkhybrid tool
Jesper Pedersen <jews@imada.ou.dk>
Pierre Pfister <pp@uplift.fr>
helped to develop the recipe on 1:1 copies.
Daniel A. Quist <dquist@cs.nmt.edu>
information about IDE CD−R and newer kernel versions
Martti.Rahkila@hut.fi
Reported problem with pre−initialized writers when booting via loadlin.
Dale Scheetz <dwarf@polaris.net>
Joerg Schilling <schilling@fokus.gmd.de>
many informations about cdrecord
Martin Schulze <joey@Infodrom.North.DE>
gave information about the cdwrite−mailinglist
6.Credits
36
CD−Writing HOWTO
Gerald C Snyder <gcsnyd@loop.com>
tested writing of an ext2 CD−ROM (see 4.4)
Art Stone <stone@math.ubc.ca>
had the idea to put non−ISO−9660 filesystems on a CD
The Sheepy One <kero@escape.com>
suggested using defective CD−ROMs as coasters for drinks
Erwin Zoer <ezoer@wxs.nl>
Futhermore, I would like to thank the following people for reporting spelling mistakes: Bartosz Maruszewski
<B.Maruszewski@zsmeie.torun.pl>, Alessandro Rubini <rubini@prosa.it>, Ian Stirling
<ian@opus131.com>, Brian H. Toby.
End of the Linux CD−Writing HOWTO. (You can stop reading here.)
6.Credits
37