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Advanced Tasks 283
Changing System Time From
Container
Normally it is impossible to change the system time from a Container. Otherwise, different
Containers could interfere with each other and could even break applications depending on the system time accuracy.
Normally only the server system administrator can change the system time. However, if you want to synchronize the time via Network Time Protocol (NTP), you have to run NTP software, which will connect to external NTP servers and update the system time. It is not advisable to run application software on the server itself, since flaws in the software can lead to compromising all Containers on this server. Thus, if you plan to use NTP, you should create a special
Container for it and configure it to have the sys_time capability. The example below illustrates configuring such a Container:
# vzctl set 101 --capability sys_time:on --save
Unable to set capability on running Container
Saved parameters for Container 101
The output of the above command warns you that vzctl cannot apply changes in the capabilities to a running Container. The Container has to be restarted before changes take effect:
# vzctl stop 101; vzctl start 101
Stopping Container ...
Container was stopped
Container is unmounted
Starting Container ...
Container is mounted
Adding IP address(es): 192.168.1.101
Hostname for Container set: Container101
Container start in progress...
# ssh root@ct101
root@ct101's password:
Last login: Mon Feb 28 23:25:58 2007 from 10.100.40.18
[root@ct101 root]# date
Mon Feb 28 23:31:57 EST 2007
[root@ct101 root]# date 10291300
Tue Feb 29 13:00:00 EST 2007
[root@ct101 root]# date
Tue Feb 29 13:00:02 EST 2007
[root@ct101 root]# logout
Connection to Container101 closed.
# date
Tue Feb 29 13:01:31 EST 2007
The command session above shows the way to change the system time from Container 101. The changes will affect all the Containers and the server itself. It is not advisable to have more than one Container with the sys_time capability set on.
NTP is described in Internet Standard RFC 1305; more information including client software can be obtained from the NTP web server (http://www.ntp.org).
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Table of contents
- 10 Preface
- 10 About This Guide
- 11 Organization of This Guide
- 12 Documentation Conventions
- 13 Getting Help
- 13 Feedback
- 14 Parallels Virtuozzo Containers Philosophy
- 14 About Parallels Virtuozzo Containers Software
- 15 What is Parallels Virtuozzo Containers
- 17 Parallels Virtuozzo Containers 64-bit vs. Parallels Virtuozzo Containers 32-bit
- 18 Distinctive Features of Parallels Virtuozzo Containers
- 18 OS Virtualization
- 19 Virtuozzo File System
- 19 Templates
- 20 Resource Management
- 20 Main Principles of Parallels Virtuozzo Containers Operation
- 21 Basics of Parallels Virtuozzo Containers Technology
- 22 Parallels Virtuozzo Containers Configuration
- 23 Understanding Licensing
- 23 Parallels Management Console Overview
- 24 Parallels Management Console Specific Features
- 25 Parallels Management Console Network Architecture
- 26 Hardware Node Main Window
- 28 Parallels Virtual Automation Overview
- 29 Parallels Power Panel Overview
- 30 Hardware Node Availability Considerations
- 31 Operations on Container
- 31 Creating New Container
- 32 Before You Begin
- 33 Choosing Container ID
- 35 Choosing OS EZ Template
- 36 List of Supported Linux Distributions for Containers
- 37 Creating Container
- 39 Creating Containers in Parallels Management Console
- 44 Configuring Container
- 44 Setting Startup Parameters
- 45 Setting Network Parameters
- 46 Setting root Password for Container
- 47 Starting, Stopping, Restarting, and Querying Status of Container
- 49 Listing Containers
- 52 Setting Name for Container
- 54 Storing Extended Information on Container
- 55 Migrating Container
- 56 Standard Migration
- 59 Zero-Downtime Migration
- 62 Moving Container Within Hardware Node
- 64 Copying Container Within Hardware Node
- 66 Backing Up and Restoring Containers
- 67 Using vzabackup/vzarestore Utilities
- 69 Managing Backups in Parallels Management Console
- 70 Setting Default Backup Parameters
- 71 Assigning Default Backup Node
- 73 Setting Default Backup Location
- 74 Defining Default Backup Compression Level
- 76 Specifying Default Backup Type
- 78 Backing Up Single Container
- 82 Backing Up Group of Containers
- 86 Browsing Backup Contents
- 88 Restoring Single Container
- 90 Restoring Container Files
- 92 Restoring Group of Containers
- 94 Managing Backup Node
- 97 Searching for Container Backups
- 99 Scheduling Container Backups
- 104 Setting Maximum Number of Backups for Parallels Power Panel
- 105 Reinstalling Container
- 107 Customizing Container Reinstallation
- 109 Deleting Container
- 111 Disabling Container
- 113 Suspending Container
- 115 Running Commands in Container
- 116 Managing Resources
- 117 What are Resource Control Parameters?
- 118 Managing Disk Quotas
- 118 What are Disk Quotas?
- 119 Disk Quota Parameters
- 120 Turning On and Off Per-Container Disk Quotas
- 123 Setting Up Per-Container Disk Quota Parameters
- 125 Turning On and Off Second-Level Quotas for Container
- 127 Setting Up Second-Level Disk Quota Parameters
- 129 Checking Quota Status
- 131 Cleaning Up Containers
- 132 Moving Container Files to the Cache Area
- 133 Associating Container Files With Application Templates
- 134 Managing Container CPU Resources
- 135 Managing CPU Share
- 137 Configuring Number of CPUs Inside Container
- 139 Controlling Container CPU Usage With VZASysD Plug-in
- 141 Managing Network Accounting and Bandwidth
- 141 Network Traffic Parameters
- 142 Configuring Network Classes
- 144 Viewing Network Traffic Statistics
- 145 Turning On and Off Network Bandwidth Management
- 147 Configuring Network Bandwidth Management for Container
- 149 Managing System Parameters
- 149 Overview
- 150 Computing Memory Usage in SLM
- 151 Controlling Memory Usage by Container
- 152 SLM Modes
- 153 Managing Container Memory Usage
- 154 Grouping Applications Inside Container
- 158 Managing Disk I/O Parameters
- 158 Configuring Container Disk I/O Priority Level
- 160 Configuring the Disk I/O Bandwidth of Containers
- 161 Viewing Disk I/O Statistics for Containers
- 162 Detecting Disk I/O Bottlenecks
- 164 Managing Container Resources Configuration
- 166 Splitting Hardware Node Into Equal Pieces
- 167 Scaling Container Configuration
- 169 Validating Container Configuration
- 171 Applying New Configuration Sample to Container
- 173 Real-Time Monitoring in Parallels Virtuozzo Containers
- 174 Monitoring Resources in Text Console
- 176 Monitoring Resources in Parallels Management Console
- 177 Using Charts Representation
- 178 Adjusting Periodicity of Refreshing Information
- 179 Adjusting Representation Scale
- 180 Adjusting Colors and Styles
- 181 Highlighting Counter
- 182 Saving Counters Configuration
- 183 Replaying Information From Logs
- 185 Using Table Representation
- 186 Subscribing to Parallels Management Console Alerts
- 189 Managing Services and Processes
- 190 What Are Services and Processes
- 191 Main Operations on Services and Processes
- 192 Managing Processes and Services
- 193 Viewing Active Processes and Services
- 196 Monitoring Processes in Real Time
- 199 Changing Services Mode
- 200 Determining Container Identifier by Process ID
- 201 Starting, Stopping, and Restarting Services
- 203 Managing Parallels Virtuozzo Containers Network
- 203 Managing Network Adapters on Hardware Node
- 204 Listing Adapters
- 206 Creating VLAN Adapter
- 208 Connecting Adapter to Virtual Network
- 209 Managing Virtual Networks
- 210 Creating Virtual Network
- 212 Listing Virtual Networks
- 213 Deleting Virtual Network
- 214 Managing Virtual Network Adapters
- 214 Container Networking Modes
- 215 venet0 Mode
- 217 veth Mode
- 218 Differences Between venet0 and veth Modes
- 219 Creating and Deleting veth Network Adapters
- 221 Configuring veth Adapter Parameters
- 224 Connecting Containers to Virtual Networks
- 227 Managing Hardware Nodes
- 227 Managing Parallels Virtuozzo Containers Licenses
- 228 Installing License
- 231 Updating License
- 232 Transferring License to Another Node
- 233 Viewing Current License
- 234 Viewing License
- 235 License Statuses
- 236 Managing Files
- 238 Uploading Files to Node
- 241 Downloading Files to Local Computer
- 242 Setting Permissions for Files on Node
- 243 Managing IP Addresses Pool on Node
- 244 Configuring Hardware Node IP Addresses Pool
- 246 Viewing Allocated IP Addresses
- 248 Advanced Tasks
- 248 Configuring Capabilities
- 249 Creating VZFS Symlinks Inside a Container
- 250 Available Capabilities for Container
- 250 Capabilities Defined by POSIX Draft
- 251 Linux-Specific Capabilities
- 252 Migrating Physical Server to Container
- 252 Migration Overview
- 253 Migration Steps
- 255 Migration Requirements
- 256 Migration Restrictions
- 257 Migrating Physical Server to Container in Command Line
- 257 Preparing Container Configuration File
- 258 Creating Container Configuration File
- 260 Editing Container Configuration File
- 262 Migrating Physical Server to Container
- 264 Migrating Physical Server to Container in Parallels Management Console
- 274 Migrating Container to Physical Server
- 274 Migration Steps
- 275 Migration Requirements
- 276 Migrating Container to Physical Server
- 276 Creating Customized Containers
- 277 Using Customized OS EZ Template
- 279 Using EZ OS Template Set
- 281 Using Customized Application Template
- 283 Changing System Time From Container
- 284 Setting Up iSCSI Environment in Parallels Virtuozzo Containers-Based Systems
- 285 Obtaining Hardware Node ID From Inside Container
- 286 Mounting /vz Partition via Parallels Virtuozzo Containers Script
- 287 Managing Mount Points Inside Container
- 289 Preserving Application Data During Container Reinstallation
- 291 Accessing Devices From Inside Container
- 293 Moving Network Adapter to Container
- 294 Enabling VPN for Container
- 295 Managing Hardware Node Resources Parameters
- 296 Setting Immutable and Append Flags for Container Files and Directories
- 296 Recreating Service Container
- 297 Customizing /proc/meminfo Output Inside Container
- 299 Creating Local Repository Mirror for vzup2date
- 300 Parallels Virtuozzo Containers Repository Structure
- 302 Creating Local Mirror
- 305 Choosing Updates for Downloading
- 307 Configuring Updates Approval Policy
- 308 Loading iptables Modules
- 308 Loading iptables Modules to Hardware Node
- 309 Loading iptables Modules to Particular Containers
- 310 Sharing File System Among Containers
- 312 Creating Configuration File for New Linux Distribution
- 313 Rebooting Container
- 313 Managing Graphical Applications Inside Container
- 314 Running Graphical Applications in X Windows
- 314 Overview
- 316 Using X Windows to Run Graphical Applications
- 318 Defining Window Manager to Run X Applications
- 320 Running Graphical Applications via VNC
- 321 VZFS v2
- 322 Advantages of VZFS v2
- 323 Inside VZFS v2
- 324 Upgrading VZFS
- 326 Restrictions
- 327 Assigning External IP Addresses to Containers
- 328 Mastering Parallels Management Console
- 329 Configuring Offline Management Parameters
- 332 Viewing Summary Pages
- 334 Managing Users and Groups Inside Container
- 336 Configuring Firewall
- 338 Managing Mount Points
- 339 Viewing System and Parallels Virtuozzo Containers Logs
- 341 Managing Files Inside Container
- 343 Searching for Containers
- 344 Managing Container Search Domains
- 345 Troubleshooting
- 346 General Considerations
- 348 Kernel Troubleshooting
- 348 Using ALT+SYSRQ Keyboard Sequences
- 349 Saving Kernel Fault (OOPS)
- 350 Finding Kernel Function That Caused D Process State
- 350 Problems With Container Management
- 351 Failure to Create a Container
- 352 Failure to Start a Container
- 353 Failure to Access Container From Network
- 353 Failure to Log In to Container
- 354 Failure to Back Up Container in Parallels Management Console
- 354 Failure to Display List of Container Backups
- 355 Problems With Container Operation
- 355 Timeout When Accessing Remote Hosts
- 355 Extraneous Backups Visible to Container in Parallels Power Panel
- 356 Problems With Physical Server Migration
- 356 Failure to Start iptables Modules After Physical Server Migration
- 357 Miscellaneous Problems
- 357 Corrupted Pseudographics in Parallels Virtuozzo Containers Utilities
- 357 Getting Technical Support
- 357 Getting Assistance With Parallels Virtuozzo Containers Installation
- 358 Preparing and Sending Questions to Technical Support
- 359 Submitting Problem Report to Technical Support
- 361 Establishing Secure Channel to Parallels Support
- 362 Setting Up Monitor Node
- 363 Configuring Serial Console on Monitor Node
- 363 Configuring Serial Parameters on Monitor Node and Hardware Node
- 364 Preparing Hardware Node for Sending Messages
- 365 Starting Messages Collection on Monitor Node
- 366 Checking That Logging Works
- 366 Setting Up netconsole
- 367 Preparing Hardware Node for Sending Kernel Messages
- 368 Determining Monitor Node MAC Address
- 369 Starting Messages Collection on Monitor Node
- 372 Preparing Monitor Node for Sending Alerts
- 373 Using External Applications for Sending Alerts
- 374 Using vzstatrep to Monitor Hardware Nodes
- 376 Glossary
- 378 Index