REDHAT GLOBAL FILE SYSTEM 4.6 Manual

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Global File System 4.6 Red Hat Global File System ISBN: N/A Publication date: ...

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This book provides information about installing, configuring, and maintaining Red Hat GFS (Red Hat Global File System). Global File System ...

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Global File System: Red Hat Global File System Copyright © You need to override this in your local ent file Red Hat, Inc. Copyright © You need to override this in your local ent file Red Hat Inc.. This material may only be distributed subject to th...

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Global File System ...

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Introduction .............................................................................................................. vii 1. Audience ...................................................................................................... vii 2. ...

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10. Suspending Activity on a File System ...........................................................37 11. Displaying Extended GFS Information and Statistics ......................................38 12. Repairing a File System ..........................

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Introduction Welcome to the Global File System Configuration and Administration document. This book provides information about installing, configuring, and maintaining Red Hat GFS (Red Hat Global File System). Red Hat GFS depends on the cluster infra...

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configuring and managing Red Hat Cluster components. • LVM Administrator's Guide: Configuration and Administration — Provides a description of the Logical Volume Manager (LVM), including information on running LVM in a clustered environment....

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italic Courier font Italic Courier font represents a variable, such as an installation directory: install_dir/bin/ bold font Bold font represents application programs and text found on a graphical interface. When shown like this: OK , it indicates a ...

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4. Feedback If you spot a typo, or if you have thought of a way to make this manual better, we would love to hear from you. Please submit a report in Bugzilla (http://bugzilla.redhat.com/bugzilla/) against the component rh-cs. Be sure to mention the ...

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Topic Reference Comment by E. Marcus and H. Stern. Wiley, 2000. Table 1. Recommended References Table Recommended References xi ...

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xii ...

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GFS Overview Red Hat GFS is a cluster file system that is available with Red Hat Cluster Suite. Red Hat GFS nodes are configured and managed with Red Hat Cluster Suite configuration and management tools. Red Hat GFS provides data sharing among GFS no...

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might require a combination of configurations shown in the examples. 1.1. Superior Performance and Scalability You can obtain the highest shared-file performance when applications access storage directly. The GFS SAN configuration in Figure 1.1, “G...

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Note Clients implementing ext2 and ext3 file systems can be configured to access their own dedicated slice of SAN storage. Figure 1.2. GFS and GNBD with a SAN 1.3. Economy and Performance Figure 1.3, “GFS and GNBD with Directly Connected Storage”...

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Figure 1.3. GFS and GNBD with Directly Connected Storage 2. GFS Functions GFS is a native file system that interfaces directly with the VFS layer of the Linux kernel file-system interface. GFS is a cluster file system that employs distributed metadat...

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• Making a File System • Mounting a File System • Unmounting a File System • GFS Quota Management • Growing a File System • Adding Journals to a File System • Direct I/O • Data Journaling • Configuring atime Updates • Suspending A...

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Software Subsystem Components Description file system. lock_harness.ko Implements a pluggable lock module interface for GFS that allows for a variety of locking mechanisms to be used (for example, the DLM lock module, lock_dlm.ko). lock_dlm.ko A lock...

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GFS nodes Determine which nodes in the Red Hat Cluster Suite will mount the GFS file systems. GNBD server nodes If you are using GNBD, determine how many GNBD server nodes are needed. Note the hostname and IP address of each GNBD server node for sett...

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8 ...

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System Requirements This chapter describes the system requirements for Red Hat GFS with Red Hat Enterprise Linux 5 and consists of the following sections: • Section 1, “Platform Requirements” • Section 2, “Red Hat Cluster Suite” • Secti...

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You must configure each GFS node in your Red Hat cluster for at least one form of fencing. Fencing is configured and managed in Red Hat Cluster Suite. For more information about fencing options, refer to Configuring and Managing a Red Hat Cluster. 4....

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Requirement Description When determining the size of your file system, you should consider your recovery needs. Running the fsck command on the file system can take a long time and consume a large amount of memory. Additionally, in the event of a dis...

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12 ...

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Getting Started This chapter describes procedures for initial setup of GFS and contains the following sections: • Section 1, “Prerequisite Tasks” • Section 2, “Initial Setup Tasks” 1. Prerequisite Tasks Before setting up Red Hat GFS, make...

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Note You can use init.d scripts included with Red Hat Cluster Suite to automate activating and deactivating logical volumes. For more information about init.d scripts, refer to Configuring and Managing a Red Hat Cluster. 2. Create GFS file systems on...

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Managing GFS This chapter describes the tasks and commands for managing GFS and consists of the following sections: • Section 1, “Making a File System” • Section 2, “Mounting a File System” • Section 3, “Unmounting a File System” �...

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Warning Make sure that you are very familiar with using the LockProtoName and LockTableName parameters. Improper use of the LockProtoName and LockTableName parameters may cause file system or lock space corruption. LockProtoName Specifies the name of...

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Complete Options Table 4.1, “Command Options: gfs_mkfs” describes the gfs_mkfs command options (flags and parameters). Flag Parameter Description -b BlockSize Sets the file-system block size to BlockSize. Default block size is 4096 bytes. -D Enab...

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Flag Parameter Description management GUI. FSName, the file-system name, can be 1 to 16 characters in length, and the name must be unique among all file systems in the cluster. -V Displays command version information. Table 4.1. Command Options: gfs_...

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In this example, the GFS file system on /dev/vg01/lvol0 is mounted on the /gfs1 directory. mount -t gfs /dev/vg01/lvol0 /gfs1 Complete Usage mount -t gfs BlockDevice MountPoint -o option The -o option argument consists of GFS-specific options (refer ...

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Option Description localcaching Caution: This option should not be used when GFS file systems are shared. GFS can then turn on selected optimization capabilities that are not available when running in cluster mode. The localcaching flag is automatica...

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Note The umount command is a Linux system command. Information about this command can be found in the Linux umount command man pages. Usage umount MountPoint MountPoint Specifies the directory where the GFS file system should be mounted. 4. GFS Quota...

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Usage Setting Quotas, Hard Limit gfs_quota limit -u User -l Size -f MountPoint gfs_quota limit -g Group -l Size -f MountPoint Setting Quotas, Warn Limit gfs_quota warn -u User -l Size -f MountPoint gfs_quota warn -g Group -l Size -f MountPoint User A...

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gfs_quota warn -g 21 -l 50 -k -f /gfs 4.2. Displaying Quota Limits and Usage Quota limits and current usage can be displayed for a specific user or group using the gfs_quota get command. The entire contents of the quota file can also be displayed usi...

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group Group: limit:LimitSize warn:WarnSize value:Value The LimitSize, WarnSize, and Value numbers (values) are in units of megabytes by default. Adding the -k, -s, or -b flags to the command line change the units to kilobytes, sectors, or file-system...

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This is necessary to avoid contention among nodes writing to the quota file, which would cause a slowdown in performance. As a user or group approaches their quota limit, GFS dynamically reduces the time between its quota-file updates to prevent the ...

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(3600 seconds) for file system /gfs on a single node. gfs_tool settune /gfs quota_quantum 3600 4.4. Disabling/Enabling Quota Enforcement Enforcement of quotas can be disabled for a file system without clearing the limits set for all users and groups....

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4.5. Disabling/Enabling Quota Accounting By default, quota accounting is enabled; therefore, GFS keeps track of disk usage for every user and group even when no quota limits have been set. Quota accounting incurs unnecessary overhead if quotas are no...

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This example enables quota accounting on file system /gfs on a single node and initializes the quota file. # gfs_tool settune /gfs quota_account 1 # gfs_quota init -f /gfs 5. Growing a File System The gfs_grow command is used to expand a GFS file sys...

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After running the gfs_grow command, run a df command to check that the new space is now available in the file system. Examples In this example, the file system on the /gfs1 directory is expanded. gfs_grow /gfs1 In this example, the state of the mount...

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The gfs_jadd command is used to add journals to a GFS file system after the device where the file system resides has been expanded. Running a gfs_jadd command on a GFS file system uses space between the current end of the file system and the end of t...

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In this example, two journals are added to the file system on the /gfs1 directory. gfs_jadd -j2 /gfs1 In this example, the current state of the file system on the /gfs1 directory is checked for the new journals. gfs_jadd -Tv /gfs1 Complete Usage gfs_...

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Flag Parameter Description verbosity level to display more information. -q Quiet. Turns down the verbosity level. -V Displays command version information. -v Turns up the verbosity of messages. Table 4.4. GFS-specific Options Available When Adding Jo...

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Setting the directio Flag gfs_tool setflag directio File Clearing the directio Flag gfs_tool clearflag directio File File Specifies the file where the directio flag is assigned. Example In this example, the command sets the directio flag on the file ...

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Directory Specifies the directory where the inherit_directio flag is set. Example In this example, the command sets the inherit_directio flag on the directory named /gfs1/data/. gfs_tool setflag inherit_directio /gfs1/data/ 8. Data Journaling Ordinar...

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Directory Specifies the directory where the flag is set or cleared. File Specifies the zero-length file where the flag is set or cleared. Examples This example shows setting the inherit_jdata flag on a directory. All files created in the directory or...

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9.1. Mount with noatime A standard Linux mount option, noatime, can be specified when the file system is mounted, which disables atime updates on that file system. Usage mount -t gfs BlockDevice MountPoint -o noatime BlockDevice Specifies the block d...

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gfs_tool gettune MountPoint MountPoint Specifies the directory where the GFS file system is mounted. Changing the atime_quantum Parameter Value gfs_tool settune MountPoint atime_quantum Seconds MountPoint Specifies the directory where the GFS file sy...

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gfs_tool freeze MountPoint End Suspension gfs_tool unfreeze MountPoint MountPoint Specifies the file system. Examples This example suspends writes to file system /gfs. gfs_tool freeze /gfs This example ends suspension of writes to file system /gfs. g...

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The df flag displays a space-usage summary of a given file system. The information is more detailed than a standard df. Displaying Extended Status gfs_tool stat File The stat flag displays extended status information about a file. MountPoint Specifie...

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The gfs_fsck command has changed from previous releases of Red Hat GFS in the following ways: • You can no longer set the interactive mode with Ctrl-C. Pressing Ctrl-C now cancels the gfs_fsck command. Do not press Ctrl-C unless you want to cancel ...

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13. Context-Dependent Path Names Context-Dependent Path Names (CDPNs) allow symbolic links to be created that point to variable destination files or directories. The variables are resolved to real files or directories each time an application follows...

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Variable Description @mach This variable resolves to a real file or directory name with the machine-type string produced by the output of the following command: echo `uname -m` @os This variable resolves to a real file or directory named with the ope...

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fileC Example 43 ...

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44 ...

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Appendix A. Upgrading GFS To upgrade a node to Red Hat GFS 6.1 from earlier versions of Red Hat GFS, you must convert the GFS cluster configuration archive (CCA) to a Red Hat Cluster Suite cluster configuration system (CCS) configuration file (/etc/c...

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# service pool stop e. Uninstall Red Hat GFS RPMs. 2. Install new software: a. Install Red Hat Enterprise Linux version 4 software (or verify that it is installed). b. Install Red Hat Cluster Suite and Red Hat GFS RPMs. 3. At all GFS 6.1 nodes, creat...

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vgconvert command as shown in the following example: # vgconvert -M2 argus Volume group argus successfully converted 7. At all GFS 6.1 nodes, run vgchange -ay as shown in the following example: # vgchange -ay 1 logical volume(s) in volume group "...

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Index A adding journals to a file system, 29 atime, configuring updates, 35 mounting with noatime, 36 tuning atime quantum, 36 audience, vii C CDPN variable values table, 41 configuration, before, 6 configuration, initial, 13 prerequisite tasks, 13 c...

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growing a file system, 28 I initial tasks setup, initial, 13 introduction, vii audience, vii references, x M making a file system, 15 managing GFS, 15 mount table, 19 mounting a file system, 18 N network power switches system requirements, 11 O overv...