User manual REDHAT GLOBAL FILE SYSTEM 5.1

[. . . ] Global File System 5. 1 Red Hat Global File System ISBN: N/A Publication date: Global File System This book provides information about installing, configuring, and maintaining Red Hat GFS; (Red Hat Global File System). 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 the terms and conditions set forth in the Open Publication License, V1. 0 or later with the restrictions noted below (the latest version of the OPL is presently available at http://www. opencontent. org/openpub/). Distribution of substantively modified versions of this document is prohibited without the explicit permission of the copyright holder. Distribution of the work or derivative of the work in any standard (paper) book form for commercial purposes is prohibited unless prior permission is obtained from the copyright holder. [. . . ] The file system contains eight journals and is created on /dev/vg01/lvol1. gfs_mkfs -p lock_dlm -t alpha:gfs2 -j 8 /dev/vg01/lvol1 16 Complete Options Complete Options Table 4. 1, "Command Options: gfs_mkfs" describes the gfs_mkfs command options (flags and parameters). Flag -b Parameter BlockSize Description Sets the file-system block size to BlockSize. Displays available options. -D -h -J MegaBytes Specifies the size of the journal in megabytes. Specifies the number of journals to be created by the gfs_mkfs command. One journal is required for each node that mounts the file system. Note: More journals than are needed can be specified at creation time to allow for future expansion. -j Number -p LockProtoName Specifies the name of the locking protocol to use. Recognized cluster-locking protocols include: lock_dlm -- The standard locking module. lock_nolock -- May be used when GFS is acting as a local file system (one node only). -O Prevents the gfs_mkfs command from asking for confirmation before writing the file system. Do not display anything. MegaBytes -q -r Specifies the size of the resource groups in megabytes. Default resource group size is 256 megabytes. Specifies the journal-segment size in file-system blocks. This parameter has two parts separated by a colon (no spaces) as follows: ClusterName:FSName. ClusterName is the name of the Red Hat cluster for which the GFS file system is being created. The cluster name is set in the /etc/cluster/cluster. conf file via the Cluster Configuration Tool and displayed at the Cluster Status Tool in the Red Hat Cluster Suite cluster management GUI. FSName, the file-system name, can be 1 to 16 17 -s Blocks -t LockTableName Chapter 4. Managing GFS Flag Parameter Description characters in length, and the name must be unique among all file systems in the cluster. -V Displays command version information. Table 4. 1. Mounting a File System Before you can mount a GFS file system, the file system must exist (refer to Section 1, "Making a File System"), the volume where the file system exists must be activated, and the supporting clustering and locking systems must be started (refer to Chapter 3, Getting Started and Configuring and Managing a Red Hat Cluster. After those requirements have been met, you can mount the GFS file system as you would any Linux file system. To manipulate file ACLs, you must mount the file system with the -o acl mount option. If a file system is mounted without the -o acl mount option, users are allowed to view ACLs (with getfacl), but are not allowed to set them (with setfacl). Usage Mounting Without ACL Manipulation mount -t gfs BlockDevice MountPoint Mounting With ACL Manipulation mount -t gfs -o acl BlockDevice MountPoint -o acl GFS-specific option to allow manipulating file ACLs. BlockDevice Specifies the block device where the GFS file system resides. MountPoint Specifies the directory where the GFS file system should be mounted. Example In this example, the GFS file system on /dev/vg01/lvol0 is mounted on the /gfs1 directory. 18 Complete Usage 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 to Table 4. 2, "GFS-Specific Mount Options") or acceptable standard Linux mount -o options, or a combination of both. Multiple option parameters are separated by a comma and no spaces. Note The mount command is a Linux system command. In addition to using GFS-specific options described in this section, you can use other, standard, mount command options (for example, -r). [. . . ] · You can decrease the level of verbosity by using the -q flag. Adding a second -q flag decreases the level again. · The -n option opens a file system as read-only and answers no to any queries automatically. The option provides a way of trying the command to reveal errors without actually allowing the gfs_fsck command to take effect. [. . . ]