Getting started. Imagine communications Farad 2300 RAIDar
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1 Getting started
RAIDar is a web-based application for configuring, monitoring, and managing the storage system.
Each controller module in the storage system contains a web server, which is accessed when you sign in to
RAIDar. In a dual-controller system, you can access all functions from either controller. If one controller becomes unavailable, you can continue to manage the storage system from the partner controller.
RAIDar is also referred to as the WBI.
Although the RAIDar interface will only display the health of a single Farad stack, you can use Farad Storage
Manager to view health of and access to multiple Farad Gen 1 and Gen 2 stacks from a single display. See the
Farad Storage Manager User Guide for more information.
NOTE: Open WBI sessions can negatively impact system performance.
Configuring and provisioning a new storage system
See the Farad Infrastructure Commissioning Checklist for the latest information on how to setup and configure a system for the first time.
You can make additional configuration and provisioning changes and view system status, as described in later chapters of this guide.
Browser setup
• Use Mozilla Firefox 3 or later, or Microsoft Internet Explorer 8 or later.
• To see the help window, you must enable pop-up windows.
• To optimize the display, use a color monitor and set its color quality to the highest setting.
• To navigate beyond the Sign In page (with a valid user account):
• Set the browser’s local-intranet security option to medium or medium-low. For Internet Explorer 8, adding each controller’s network IP address as a trusted site can avoid access issues.
• Verify that the browser is set to allow cookies at least for the IP addresses of the storage-system network ports.
Signing in
To sign in:
1. In the web browser’s address field, type the IP address of a controller network port and press Enter. The
RAIDar Sign In page is displayed. If the Sign In page does not display, verify that you have entered the correct
IP address.
2. On the Sign In page, enter the name and password of a configured user. The default user name and password are manage and !manage. To display the interface in a language other than the user setting, select the language from the Language list.
Language preferences can be configured for the system and for individual users.
3. Click Sign In. If the system is available, the System Overview page is displayed; otherwise, a message indicates that the system is unavailable.
Tips for signing in and signing out
• Do not include a leading zero in an IP address. For example, enter 10.1.4.6 not 10.1.4.06.
• Multiple users can be signed in to each controller simultaneously.
• For each active RAIDar session an identifier is stored in the browser. Depending on how your browser treats this session identifier, you might be able to run multiple independent sessions simultaneously. Internet
NEXIO Farad 2300 Series WBI User Guide 11
Explorer can run separate RAIDar sessions if you select New Session in the File menu. If you do not select this then all instances of Internet Explorer share the same session, as does Firefox.
• End a RAIDar session by clicking the Sign Out link near the top of the RAIDar window. Do not simply close the browser window.
Tips for using the main window
• The Configuration View panel displays logical and physical components of the storage system. To perform a task, select the component to act on and then either:
• Right-click to display a context menu and select the task to perform. This is the method that help topics describe.
• Click a task category in the main panel and select the task to perform.
• The System Status panel displays System Time and System Events. System Events shows how many events of each severity have occurred in the system. To view event details, click a severity icon. For more information
see Viewing the system event log on page 73.
• Many tables can be sorted by a specific column. To do so, click the column heading to sort low to high; click again to sort high to low. In tables that allow a task to be performed on multiple items, you can select up to 100 items or clear all selections by toggling the checkbox in the table’s heading row.
• Do not use the browser’s Back, Forward, Reload, or Refresh buttons. RAIDar has a single page whose content changes as you perform tasks and automatically updates to show current data.
• A red asterisk ( * ) identifies a required setting.
• The icon in the upper right corner of the main window shows the status of communication between RAIDar, the MC, and the SC, as described in the following table.
Table 3 RAIDar communication status icons
Icon Meaning
RAIDar can communicate with the MC, which can communicate with the SC.
RAIDar cannot communicate with the MC.
RAIDar can communicate with the MC, which cannot communicate with the SC.
• Below the communication status icon, a timer shows how long the session can be idle until you are automatically signed out. This timer resets after each action you perform. One minute before automatic sign-out you are prompted to continue using RAIDar.
• If a RAIDar session is active on a controller and the controller is power cycled or is forced offline by the partner controller or certain other events occur, the session might hang. RAIDar might say that it is
“Connecting” but stop responding, or the page may become blank with the browser status “Done.” After the controller comes back online, the session will not restart. To continue using RAIDar, close and reopen the browser and start a new RAIDar session.
•
•
Tips for using the help window
• To display help for a component in the Configuration View panel, right-click the component and select Help.
To display help for the content in the main panel, click either Help in the menu bar or the help icon in the upper right corner of the panel.
• In the help window, click the table of contents icon to show or hide the Contents pane.
12 Getting started
• As the context in the main panel is changed, the corresponding help topic is displayed in the help window. To prevent this automatic context-switching, click the pin icon . When a help window is pinned ( ), you can still browse to other topics within the help window and you can open a new help window. You cannot unpin a help window; you can only close it.
• If you have viewed more than one help topic, you can click the arrow icons to display the previous or next topic.
System concepts
About user accounts
The system provides three default user accounts and allows a maximum of 12 user accounts to be configured. Any account can be modified or removed except you cannot remove the user you are signed in as.
The default user accounts are for general users that can access the WBI (RAIDar), CLI, FTP, or SMI-S interfaces.
You can also create SNMPv3 user accounts that can access the MIB or receive trap notifications. SNMPv3 user accounts support SNMPv3 security features such as authentication and encryption. For information about configuring trap notifications, see
Configuring SNMP notification on page 32. For information about the MIB, see
General user accounts have these options:
• User Name.
• Password.
• User Roles. Select Monitor or Manage. You cannot change the roles of user manage.
• Monitor. The user has access to the WBI and CLI. A user with role Monitor may view system settings but cannot change them.
• Manage. The user has access to the WBI, CLI, FTP interface, and SMI-S interface. A user with role
Manage may view and change system settings.
• User Type. Identifies the user’s experience level: Standard, Advanced, or Diagnostic.
• WBI Access. Allows access to the web-based management interface.
• CLI Access. Allows access to the command-line management interface.
• FTP Access. Allows access to the FTP interface, which can be used instead of the WBI to install firmware updates and download logs.
• SMI-S Access. Allows access to the SMI-S interface, used for remote management of the system through your network.
• Base Preference. The base for entry and display of storage-space sizes. In base 2, sizes are shown as powers of
2, using 1024 as a divisor for each magnitude. In base 10, sizes are shown as powers of 10, using 1000 as a divisor for each magnitude. Operating systems usually show volume size in base 2. Disk drives usually show size in base 10. Memory (RAM and ROM) size is always shown in base 2.
• Precision Preference. The number of decimal places (1–10) for display of storage-space sizes.
• Unit Preference. The unit for display of storage-space sizes: Auto, TB, GB, or MB.
The Auto option lets the system determine the proper unit for a size. Based on the precision setting, if the selected unit is too large to meaningfully display a size, the system uses a smaller unit for that size. For example, if the unit is set to TB, precision is set to 1, and base is set to 10, the size 0.11709 TB is shown as
117.1 GB.
• Temperature Preference. The scale for display of temperature values: Celsius or Fahrenheit.
• Auto Sign Out. The amount of time that the user’s session can be idle before the user is automatically signed out (2–720 minutes). Note: It is recommended that this value remain at the default setting of 30 minutes.
• Locale. The user’s preferred display language, which overrides the system’s default display language.
Installed language sets include Chinese-Simplified, Chinese-Traditional, Dutch, English, French, German,
Italian, Japanese, Korean, and Spanish.
SNMPv3 user accounts have these options:
• User Name.
• Password.
NEXIO Farad 2300 Series WBI User Guide 13
• SNMP user type. Either: User Access, which allows the user to view the SNMP MIB; or Trap Target, which allows the user to receive SNMP trap notifications. Trap Target uses the IP address set with the Trap Host
Address option.
• Authentication Type. Either: MD5 authentication; SHA authentication; or none (no authentication).
Authentication uses the password set with the Password option.
• Privacy Type. Either: DES; AES; or none (no encryption). Encryption uses the password set with the Privacy
Password option.
• Privacy Password. The encryption password.
• Trap Host Address. The IP address of the host system that will receive SNMP traps.
Table 4 Settings for default users
Locale Name monitor !monitor
manage !manage
ftp
Password
!ftp
Roles Type Interfaces enabled
Monitor Standard WBI, CLI 10
Monitor,
Manage
WBI, CLI,
FTP,
SMI-S
Monitor,
Manage
FTP
Base Prec.
Units Temp.
Auto
Sign
Out
1 Auto Celsius 30
Min.
English
NOTE: To secure the storage system, set a new password for each default user.
Related topics
•
Configuring user accounts on page 33
About vdisks
A vdisk is a virtual disk that is composed of one or more disks, and has the combined capacity of those disks. The number of disks that a vdisk can contain is determined by its RAID level. All disks in a vdisk must be the same type (SAS SSD, enterprise SAS, or midline SAS). A maximum of 64 vdisks per controller and 128 per system can exist. A vdisk is equilavent to an array in Farad Gen 1 and would have a name in the format of Grp 001, Grp 002, etc.
See the Farad Infrastructure Commissioning Checklist for details on creating the naming vdisks.
A vdisk can contain different models of disks, and disks with different capacities. For example, a vdisk can include a 500 GB disk and a 750 GB disk. If you mix disks with different capacities, the smallest disk determines the logical capacity of all other disks in the vdisk, regardless of RAID level. For example, if a RAID0 vdisk contains one 500 GB disk and four 750 GB disks, the capacity of the vdisk is equivalent to approximately five 500
GB disks.
Each disk has metadata that identifies whether the disk is a member of a vdisk, and identifies other members of that vdisk. This enables disks to be moved to different slots in a system; an entire vdisk to be moved to a different system; and a vdisk to be quarantined if disks are detected missing.
When a vdisk is created the system automatically assigns the owner to balance the number of vdisks each controller owns.
In a dual-controller system, when a controller fails, the partner controller assumes temporary ownership of the failed controller’s vdisks and resources. If a fault-tolerant cabling configuration is used to connect the controllers to drive enclosures and hosts, both controllers’ LUNs are accessible through the partner.
When you create a vdisk you should specify a chunk size and other settings as described in the Farad
Infrastructure Commissioning Checklist. The following information is provided for the reader’s information only.
The chunk size is the amount of contiguous data that is written to a disk before moving to the next disk. After a vdisk is created its chunk size cannot be changed. For example, if the host is writing data in 16 KB transfers, that
14 Getting started
size would be a good choice for random transfers because one host read would generate the read of exactly one disk in the volume. That means if the requests are random-like, then the requests would be spread evenly over all of the disks, which is good for performance. If you have 16 KB accesses from the host and a 64 KB block size, then some of the hosts accesses would hit the same disk; each chunk contains four possible 16 KB groups of data that the host might want to read, which is not an optimal solution. Alternatively, if the host accesses were 128 KB, then each host read would have to access two disks in the vdisk. For random patterns, that ties up twice as many disks.
When you create a vdisk you can also create volumes within it. A volume is a logical subdivision of a vdisk, and can be mapped to controller host ports for access by hosts. The storage system presents only volumes, not vdisks, to hosts. A “volume” is the equivalent to a “disk” in Farad Gen 1 and would have a name in the format of Disk
001, Disk 002, etc.
See the Farad Infrastructure Commissioning Checklist for details on creating and naming volumes.
Related topics
•
•
•
• Vdisk topics in
Provisioning the system on page 47
•
Configuring an existing vdisk on page 44
•
Verifying a vdisk (Not supported in Farad Gen 2) on page 66
•
Scrubbing a vdisk (Not supported in Farad Gen 2) on page 67
•
Viewing information about a vdisk ( page 75
), all vdisks (
•
Removing a vdisk from quarantine on page 67
About spares
A controller automatically reconstructs or rebuilds a fault-tolerant vdisk (RAID 6) when one or more of its disks fails and a compatible spare disk is available. A compatible disk has enough capacity to replace the failed disk and is the same type (SAS SSD, enterprise SAS, or midline SAS).
There are three types of spares:
• Dedicated spare. Reserved for use by a specific vdisk to replace a failed disk. Most secure way to provide spares for vdisks but expensive to reserve a spare for each vdisk. Dedicated spare is not supported in Farad
Gen 2.
• Global spare. Reserved for use by any fault-tolerant vdisk to replace a failed disk.
• Dynamic spare. An available compatible disk that is automatically assigned to replace a failed disk in a fault-tolerant vdisk. Dynamic spare is not supported in Farad Gen 2.
When a disk fails, the system looks for a dedicated spare first. If it does not find a dedicated spare, it looks for a global spare. If it does not find a compatible global spare and the dynamic spares option is enabled, it takes any available compatible disk. If no compatible disk is available, reconstruction cannot start.
TIP: For more information in setting up Global Spares, see the Farad Infrastructure Commissioning Checklist.
Related topics
•
Configuring dynamic spares (Not supported in Farad Gen 2) on page 39
•
Managing dedicated spares (Not supported in Farad Gen 2) on page 44
•
Managing global spares on page 51
•
Using the Provisioning Wizard on page 47
•
•
Viewing information about a vdisk ( page 75
) or all vdisks (
NEXIO Farad 2300 Series WBI User Guide 15
About volumes
A volume is a logical subdivision of a vdisk, and can be mapped to controller host ports for access by hosts. A mapped volume provides the storage for a file system partition you create with your operating system or third-party tools. The storage system presents only volumes, not vdisks, to hosts. A vdisk can have a maximum of
128 volumes. For Farad Gen 2, each vdisk has only one associated volume.
You can create a vdisk that has one volume or multiple volumes. Multiple volumes in a single vdisk are not supported in Farad Gen 2. See the Farad Infrastructure Commissioning Checklist for more information on setting up volumes.
• Single-volume vdisks work well in environments that need one large, fault-tolerant storage space for data on one host. A large database accessed by users on a single host that is used only for that application is an example.
• Multiple-volume vdisks (not supported in Farad Gen 2) work well when you have very large disks and you want to make the most efficient use of disk space for fault tolerance (parity and spares). For example, you could create one 10 TB RAID5 vdisk and dedicate one spare to the vdisk. This minimizes the amount of disk space allocated to parity and spares compared to the space required if you created five 2 TB RAID5 vdisks.
However, I/O to multiple volumes in the same vdisk can slow system performance.
When you create volumes you can specify their sizes. If the total size of a vdisk’s volumes equals the size of the vdisk, you will not have any free space. Without free space, you cannot add or expand volumes. If you need to add or expand a volume in a vdisk without free space, you can delete a volume to create free space. Or, you can expand the vdisk and then either add a volume or expand a volume to use the new free space.
You can use a volume’s default name or change it to identify the volume’s purpose. For example, a volume used to store payroll information can be named Payroll.
You can create vdisks with volumes by using the Provisioning Wizard, or you can create volumes manually.
Related topics
•
•
About volume mapping on page 17
•
About volume cache options on page 17
• Volume topics in
Provisioning the system on page 47
•
Changing a volume’s name on page 45
•
Changing a volume’s cache settings on page 45
•
Viewing information about a volume on page 78
About hosts
A host identifies an external port that the storage system is attached to. The external port may be a port in an I/O adapter, such as an FC HBA, in a server, or a port in a network switch.
The controllers automatically discover hosts that have sent an inquiry
command or a report luns
command to the storage system. Hosts typically do this when they boot up or rescan for devices. When the command from the host occurs, the system saves the host ID. The ID for an FC or SAS host is its WWPN. You can also manually create entries for hosts.
You can assign a name to a host to make it easy to recognize for volume mapping. A maximum of 64 names can be assigned.
The Configuration View panel lists hosts by name, or if they are unnamed, by ID.
Related topics
•
Using the Configuration Wizard on page 27
•
Changing host interface settings on page 37
•
•
•
Changing a host’s name on page 56
16 Getting started
•
Changing host mappings on page 56
• Viewing information about a host (
page 80 ) or all hosts ( page 80
)
About volume mapping
Each volume has default host-access settings that are set when the volume is created; these settings are called the
default mapping. The default mapping applies to any host that has not been explicitly mapped using different settings. Explicit mappings for a volume override its default mapping. Explicit mappings are not supported in
Farad Gen 2.
Default mapping enables all attached hosts to see a volume using a specified LUN and access permissions set by the administrator. This means that when the volume is first created, all connected hosts can immediately access the volume using the advertised default mapping settings. This behavior is expected by some operating systems, such as Microsoft Windows, which can immediately discover the volume. The advantage of a default mapping is that all connected hosts can discover the volume with no additional work by the administrator. The disadvantage is that all connected hosts can discover the volume with no restrictions. Therefore, this process is not recommended for specialized volumes that require restricted access.
You can change a volume’s default mapping, and create, modify, or delete explicit mappings. A mapping can specify read-write, read-only, or no access through one or more controller host ports to a volume. When a mapping specifies no access, the volume is masked. You can apply access privileges to one or more of the host ports on either controller. To maximize performance, map a volume to at least one host port on the controller that owns it.
To sustain I/O in the event of controller failure, map to at least one host port on each controller.
For example, a payroll volume could be mapped with read-write access for the Human Resources host and be masked for all other hosts. An engineering volume could be mapped with read-write access for the Engineering host and read-only access for other departments’ hosts.
A LUN identifies a mapped volume to a host. Both controllers share a set of LUNs, and any unused LUN can be assigned to a mapping; however, each LUN can only be used once per volume as its default LUN. For example, if
LUN 5 is the default for Volume1, no other volume in the storage system can use LUN 5 as its default LUN. For explicit mappings, the rules differ: LUNs used in default mappings can be reused in explicit mappings for other volumes and other hosts.
TIP: When an explicit mapping is deleted, the volume’s default mapping takes effect. Therefore, it is recommended to use the same LUN for explicit mappings as for the default mapping.
Volume mapping settings are stored in disk metadata. If enough of the disks used by a volume are moved into a different enclosure, the volume’s vdisk can be reconstructed and the mapping data is preserved.
The 4000 Series storage-system models use ULP, which can expose all LUNs through all host ports on both controllers. The interconnect information is managed in the controller firmware. ULP appears to the host as an active-active storage system where the host can choose any available path to access a LUN regardless of vdisk ownership. When ULP is in use, the controllers’ operating/redundancy mode is shown as Active-Active ULP.
ULP uses the T10 Technical Committee of INCITS ALUA extensions, in SPC-3, to negotiate paths with aware host systems. Unaware host systems see all paths as being equal.
Related topics
•
Using the Provisioning Wizard on page 47
•
Changing a volume’s default mapping ( page 53
) or explicit mappings (
)
•
Changing host mappings on page 56
• Viewing information about a volume (
page 80 ), or all hosts ( page 80
)
About volume cache options
You can set options that optimize reads and writes performed for each volume. See the Farad Infrastructure
Commissioning Checklist for more information on setting cache options.
NEXIO Farad 2300 Series WBI User Guide 17
Using write-back or write-through caching
CAUTION: Only disable write-back caching if you fully understand how the host operating system, application, and adapter move data. If used incorrectly, you might hinder system performance.
You can change a volume’s write-back cache setting. Write-back is a cache-writing strategy in which the controller receives the data to be written to disks, stores it in the memory buffer, and immediately sends the host operating system a signal that the write operation is complete, without waiting until the data is actually written to the disk.
Write-back cache mirrors all of the data from one controller module cache to the other. Write-back cache improves the performance of write operations and the throughput of the controller.
When write-back cache is disabled, write-through becomes the cache-writing strategy. Using write-through cache, the controller writes the data to the disks before signaling the host operating system that the process is complete.
Write-through cache has lower write operation and throughput performance than write-back, but it is the safer strategy, with minimum risk of data loss on power failure. However, write-through cache does not mirror the write data because the data is written to the disk before posting command completion and mirroring is not required. You can set conditions that cause the controller to change from write-back caching to write-through caching.
In both caching strategies, active-active failover of the controllers is enabled.
You can enable and disable the write-back cache for each volume. By default, volume write-back cache is enabled.
Because controller cache is backed by super-capacitor technology, if the system loses power, data is not lost. For most applications, this is the correct setting.
If you are doing random access to this volume, leave the write-back cache enabled.
TIP: The best practice for a fault-tolerant configuration is to use write-back caching.
Optimizing read-ahead caching (Not supported in Farad Gen 2)
CAUTION: Only change read-ahead cache settings if you fully understand how the host operating system, application, and adapter move data so that you can adjust the settings accordingly.
You can optimize a volume for sequential reads or streaming data by changing its read-ahead cache settings. Read ahead is triggered by two back-to-back accesses to consecutive LBA ranges, whether forward (increasing LBAs) or reverse (decreasing LBAs).
You can change the amount of data read in advance after two back-to-back reads are made. Increasing the read-ahead cache size can greatly improve performance for multiple sequential read streams; however, increasing read-ahead size will likely decrease random read performance.
• The Default option works well for most applications: it sets one chunk for the first access in a sequential read and one stripe for all subsequent accesses. The size of the chunk is based on the chunk size used when you created the vdisk (the default is 64 KB). Non-RAID and RAID1 vdisks are considered to have a stripe size of
64 KB.
• Specific size options let you select an amount of data for all accesses.
• The Maximum option lets the controller dynamically calculate the maximum read-ahead cache size for the volume. For example, if a single volume exists, this setting enables the controller to use nearly half the memory for read-ahead cache.
Only use Maximum when disk latencies must be absorbed by cache. For example, for read-intensive applications, you will want data that is most often read to be in cache so that the response to the read request is very fast; otherwise, the controller has to locate which disks the data is on, move it up to cache, and then send it to the host. Do not use Maximum if more than two volumes are owned by the controller on which the read-ahead setting is being made. If there are more than two volumes, there is contention on the cache as to which volume’s read data should be held and which has the priority; each volume constantly overwrites the other volume’s data in cache, which could result in taking a lot of the controller’s processing power.
18 Getting started
• The Disabled option turns off read-ahead cache. This is useful if the host is triggering read ahead for what are random accesses. This can happen if the host breaks up the random I/O into two smaller reads, triggering read ahead.
You can also change the optimization mode.
• The Standard read-ahead caching mode works well for typical applications where accesses are a combination of sequential and random; this method is the default. For example, use this mode for transaction-based and database update applications that write small files in random order.
• You can use No-mirror mode. When this mode is enabled, each controller stops mirroring its cache metadata to the partner controller. This improves write I/O response time but at the risk of losing data during a failover.
ULP behavior is not affected, with the exception that during failover any write data in cache will be lost.
Related topics
•
Changing a volume’s cache settings on page 45
•
Changing system cache settings on page 40
•
Viewing information about a volume on page 78
About RAID levels
Farad Gen 2 uses RAID 6 only. The following information is provided for the reader’s information only. The
RAID controllers enable you to set up and manage vdisks, whose storage may be spread across multiple disks.
This is accomplished through firmware resident in the RAID controller. RAID refers to vdisks in which part of the storage capacity may be used to achieve fault tolerance by storing redundant data. The redundant data enables the system to reconstruct data if a disk in the vdisk fails.
Hosts see each partition of a vdisk, known as a volume, as a single disk. A volume is actually a portion of the storage space on disks behind a RAID controller. The RAID controller firmware makes each volume appear as one very large disk. Depending on the RAID level used for a vdisk, the disk presented to hosts has advantages in fault-tolerance, cost, performance, or a combination of these.
NOTE: Choosing the right RAID level for your application improves performance.
The following tables:
• Provide examples of appropriate RAID levels for different applications
• Compare the features of different RAID levels
• Describe the expansion capability for different RAID levels
Table 5 Example applications and RAID levels
Application
Testing multiple operating systems or software development (where redundancy is not an issue)
Fast temporary storage or scratch disks for graphics, page layout, and image rendering
Workgroup servers
Video editing and production
Network operating system, databases, high availability applications, workgroup servers
Very large databases, web server, video on demand
Mission-critical environments that demand high availability and use large sequential workloads
RAID level
5
50
6
NRAID
0
1 or 10
3
NEXIO Farad 2300 Series WBI User Guide 19
Table 6 RAID level comparison
RAID level
Min. disks
Description
NRAI
D
0
1
3
5
6
10
(1+0)
50
(5+0)
1
2
2
3
3
4
4
6
Non-RAID, nonstriped mapping to a single disk
Data striping without redundancy
Disk mirroring
Block-level data striping with dedicated parity disk
Block-level data striping with distributed parity
Block-level data striping with double distributed parity
Stripes data across multiple RAID1 sub-vdisks
Stripes data across multiple RAID5 sub-vdisks
Strengths Weaknesses
Ability to use a single disk to store additional data
Highest performance
Not protected, lower performance
(not striped)
No data protection: if one disk fails all data is lost
Very high performance and data protection; minimal penalty on write performance; protects against single disk failure
High redundancy cost overhead: because all data is duplicated, twice the storage capacity is required
Excellent performance for large, sequential data requests (fast read); protects against single disk failure
Not well-suited for transaction-oriented network applications: single parity disk does not support multiple, concurrent write requests
Best cost/performance for transaction-oriented networks; very high performance and data protection; supports multiple simultaneous reads and writes; can also be optimized for large, sequential requests; protects against single disk failure
Write performance is slower than
RAID0 or RAID1
Best suited for large sequential workloads; non-sequential read and sequential read/write performance is comparable to RAID5; protects against dual disk failure
Higher redundancy cost than RAID5 because the parity overhead is twice that of RAID5; not well-suited for transaction-oriented network applications; non-sequential write performance is slower than RAID5
Highest performance and data protection (protects against multiple disk failures)
High redundancy cost overhead: because all data is duplicated, twice the storage capacity is required; requires minimum of four disks
Better random read and write performance and data protection than RAID5; supports more disks than RAID5; protects against multiple disk failures
Lower storage capacity than RAID5
Table 7 Vdisk expansion by RAID level (Not supported in Farad Gen 2)
Expansion capability RAID level
NRAID
0, 3, 5, 6
1
10
50
Cannot expand.
You can add 1–4 disks at a time.
Cannot expand.
You can add 2 or 4 disks at a time.
You can add one sub-vdisk at a time. The added sub-vdisk must contain the same number of disks as each of the existing sub-vdisks.
Maximum disks
1
16
2
16
32
20 Getting started
About size representations
Parameters such as names of users and volumes have a maximum length in bytes. ASCII characters are 1 byte; most Latin (Western European) characters with diacritics are 2 bytes; most Asian characters are 3 bytes.
Operating systems usually show volume size in base 2. Disk drives usually show size in base 10. Memory (RAM and ROM) size is always shown in base 2. In RAIDar, the base for entry and display of storage-space sizes can be set per user or per session. When entering storage-space sizes only, either base-2 or base-10 units can be specified.
Table 8 Size representations in base 2 and base 10
Base 2
Unit
KiB (kibibyte) 1,024
MiB (mebibyte)
1,024
2
GiB (gibibyte)
1,024
3
TiB (tebibyte)
1,024
4
PiB (pebibyte)
1,024
5
EiB (exbibyte)
1,024
6
Size in bytes
Base 10
Unit Size in bytes
KB (kilobyte) 1,000
MB (megabyte)
1,000
2
GB (gigabyte)
1,000
3
TB (terabyte)
PB (petabyte)
EB (exabyte)
1,000
4
1,000
5
1,000
6
The locale setting determines the character used for the decimal (radix) point, as shown below.
Table 9 Decimal (radix) point character by locale
Language
English, Chinese, Japanese, Korean
Dutch, French, German, Italian, Spanish
Character Examples
Period (.) 146.81 GB
3.0 Gbit/s
Comma (,) 146,81 GB
3,0 Gbit/s
Related topics
•
About user accounts on page 13
About the system date and time
You can change the storage system’s date and time, which are displayed in the System Status panel. It is important to set the date and time so that entries in system logs and event-notification email messages have correct time stamps.
You can set the date and time manually or configure the system to use NTP to obtain them from a network-attached server. When NTP is enabled, and if an NTP server is available, the system time and date can be obtained from the NTP server. This allows multiple storage devices, hosts, log files, and so forth to be synchronized. If NTP is enabled but no NTP server is present, the date and time are maintained as if NTP was not enabled.
NTP server time is provided in UTC, which provides several options:
• If you want to synchronize the times and logs between storage devices installed in multiple time zones, set all the storage devices to use UTC.
• If you want to use the local time for a storage device, set its time zone offset.
• If a time server can provide local time rather than UTC, configure the storage devices to use that time server, with no further time adjustment.
Whether NTP is enabled or disabled, the storage system does not automatically make time adjustments, such as for U.S. daylight savings time. You must make such adjustments manually.
NEXIO Farad 2300 Series WBI User Guide 21
Related topics
•
Changing the system date and time on page 36
About storage-space color codes
RAIDar panels use the following color codes to identify how storage space is used.
Table 10 Storage-space color codes
Area
Overview panels
Vdisk panels
Color Meaning
Total space
Available/free space
Used space
Reserved/overhead space, used for parity, for example
Space used by spares
Wasted space, due to use of mixed disk sizes
About Configuration View icons
The Configuration View panel uses the following icons to let you view physical and logical components of the storage system.
Table 11 Configuration View icons
Icon Meaning
Show all subcomponents
Icon Meaning
Enclosure
Hide all subcomponents
Show the component’s subcomponents
Hide the component’s subcomponents
Storage system
Host/initiator
Vdisk volume
About disk failure and vdisk reconstruction
If one or more disks fail in a fault-tolerant vdisk (RAID 1, 3, 5, 6, 10, or 50) and compatible spares are available, the storage system automatically uses the spares to reconstruct the vdisk. Vdisk reconstruction does not require
I/O to be stopped, so the vdisk can continue to be used while the Reconstruct utility runs.
A compatible spare is one whose capacity is equal to or greater than the smallest disk in the vdisk. A compatible spare has enough capacity to replace the failed disk and is the same type (SAS SSD, enterprise SAS, or midline
SAS). If no compatible spares are available, reconstruction does not start automatically. To start reconstruction manually, replace each failed disk and then do one of the following:
• Add each new disk as a global spare. Remember that a global spare might be taken by a different critical vdisk than the one you intended. When a global spare replaces a disk in a vdisk, the global spare’s icon in the enclosure view changes to match the other disks in that vdisk.
• Enable the Dynamic Spare Capability option to use the new disks without designating them as spares.
RAID6 reconstruction behaves as follows:
• During online initialization, if one disk fails, initialization continues and the resulting vdisk will be degraded
(FTDN status). After initialization completes, the system can use a compatible spare to reconstruct the vdisk.
• During online initialization, if two disks fail, initialization stops (CRIT status). The system can use two compatible spares to reconstruct the vdisk.
• During vdisk operation, if one disk fails and a compatible spare is available, the system begins to use that spare to reconstruct the vdisk. If a second disk fails during reconstruction, reconstruction continues until it is
22 Getting started
complete, regardless of whether a second spare is available. If the spare fails during reconstruction, reconstruction stops.
• During vdisk operation, if two disks fail and only one compatible spare is available, the system waits five minutes for a second spare to become available. After five minutes, the system begins to use that spare to reconstruct one disk in the vdisk (referred to as “fail 2, fix 1” mode). If the spare fails during reconstruction, reconstruction stops.
• During vdisk operation, if two disks fail and two compatible spares are available, the system uses both spares to reconstruct the vdisk. If one of the spares fails during reconstruction, reconstruction proceeds in “fail 2, fix
1” mode. If the second spare fails during reconstruction, reconstruction stops.
When a disk fails, its Fault LED illuminates amber. When a spare is used as a reconstruction target, its Activity
LED blinks green. For details about LED states, see your product’s Setup Guide.
NOTE: Reconstruction can take hours or days to complete, depending on the vdisk RAID level and size, disk speed, utility priority, and other processes running on the storage system. You can stop reconstruction only by deleting the vdisk.
About managed logs (Not supported)
As the storage system operates, it records diagnostic data in several types of log files. The size of any log file is limited, so over time and during periods of high activity, these logs can fill up and begin overwriting their oldest data. The managed logs feature allows log data to be transferred to a log-collection system before any data is lost.
The transfer does not remove any data from the logs in the storage system. The default is disabled.
The log-collection system is a host computer that is designated to receive the log data transferred from the storage system. Because log data is transferred incrementally, the log-collection system is responsible for integrating the log data for display and analysis.
The managed logs feature can be configured to operate in push mode or pull mode:
• In push mode, when log data has accumulated to a significant size, the storage system sends notifications with attached log files via email to the log-collection system. The notification will specify the storage-system name, location, contact, and IP address, and will contain a single log segment in a compressed zip file. The log segment will be uniquely named to indicate the log-file type, the date/time of creation, and the storage system.
This information will also be in the email subject line. The file name format is logtype_yyyy_mm_dd__hh_mm_ss.zip
.
• In pull mode, when log data has accumulated to a significant size, the system sends notifications via email,
SNMP, or SMI-S to the log-collection system, which can then use FTP to transfer the appropriate logs from the storage system. The notification will specify the storage-system name, location, contact, and IP address and the log-file type that needs to be transferred.
The managed logs feature monitors the following controller-specific log files:
• EC log, which includes EC debug data, EC revisions, and PHY statistics
• SC debug log and controller event log
• SC crash logs, which include the SC boot log
• MC log
Each log-file type also contains system-configuration information. The capacity status of each log file is maintained, as well as the status of what data has already been transferred. Three capacity-status levels are defined for each log file:
• Need to transfer: The log file has filled to the threshold at which content needs to be transferred. This threshold varies for different log files. When this level is reached:
• In push mode, informational event 400 and all untransferred data is sent to the log-collection system.
• In pull mode, informational event 400 is sent to the log-collection system, which can then request the untransferred log data. The log-collection system can pull log files individually, by controller.
• Warning: The log file is nearly full of untransferred data. When this level is reached, warning event 401 is sent to the log-collection system.
NEXIO Farad 2300 Series WBI User Guide 23
• Wrapped: The log file has filled with untransferred data and has started to overwrite its oldest data. When this level is reached, informational event 402 is sent to the log-collection system.
Following the transfer of a log’s data in push or pull mode, the log’s capacity status is reset to zero to indicate that there is no untransferred data.
NOTE: In push mode, if one controller is offline its partner will send the logs from both controllers.
Alternative methods for obtaining log data are to use RAIDar’s Save Logs panel or the FTP interface’s get logs
command. These methods will transfer the entire contents of a log file without changing its capacity-status level. Use of Save Logs or get logs is expected as part of providing information for a technical support request. For information about using the Save Logs panel, see
Saving logs on page 62. For information about
using the FTP interface, see the RAIDar User Guide.
Related topics
•
Configuring email notification on page 32 (for push mode)
•
Configuring SNMP notification on page 32 (for pull mode)
•
Changing management interface settings on page 31 (to enable SNMP or SMI-S for pull mode)
•
Enabling/disabling managed logs on page 43
•
Testing notifications on page 65
About performance monitoring
The storage system samples disk-performance statistics every quarter hour and retains performance data for 6 months. You can view these historical performance statistics to identify disks that are experiencing errors or are performing poorly.
RAIDar displays historical performance statistics in graphs for ease of analysis. You can view historical performance statistics either for a single disk or for all disks in a vdisk. By default, the graphs will show the latest
50 data samples, but you can specify the time period to display. If the specified time period includes more than 50 samples, their data will be aggregated into 50 samples; the graphs show a maximum of 50 samples. Data shown will be up-to-date as of the time it is requested for display, and summary statistics will be updated when a new sample is taken.
Disk-performance graphs include:
• Data Transferred
• Data Throughput
• I/O
• IOPS
• Average Response Time
• Average I/O Size
• Disk Error Counters
• Average Queue Depth
Vdisk-performance graphs include:
• Data Transferred (B)
• Data Throughput (B/s)
• Average Response Time (
μs)
You can save historical statistics in CSV format to a file for import into a spreadsheet or other third-party application. You can also reset historical statistics, which clears the retained data and continues to gather new samples.
24 Getting started
NOTE: RAIDar does not show live statistics. For information about viewing live statistics, see the CLI
Reference Guide.
Related topics
•
Vdisk performance on page 77 (to view historical performance statistics for a vdisk)
•
Disk performance on page 83 (to view historical performance statistics for a disk)
•
Resetting historical disk-performance statistics on page 68
•
Saving historical disk-performance statistics on page 69
NEXIO Farad 2300 Series WBI User Guide 25
26 Getting started
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