User manual REDHAT GLOBAL FILE SYSTEM 4.7

[. . . ] Global File System Red Hat Global File System 4. 7 Global_File_System ISBN: N/A Publication date: July 2008 Global File System This book provides information about installing, configuring, and maintaining Red Hat GFS (Red Hat Global File System) for Red Hat Enterprise Linux 4. 7. Global File System: Red Hat Global File System Copyright © 2008 Red Hat, Inc. Copyright © 2008 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. [. . . ] 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 17 -s Blocks -t LockTableName Chapter 4. Managing GFS 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. 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 18 Complete Usage 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 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). For information about other Linux mount command options, see the Linux mount man page. Table 4. 2, "GFS-Specific Mount Options" describes the available GFS-specific -o option values that can be passed to GFS at mount time. Option acl Description Allows manipulating file ACLs. If a file system is mounted without the acl mount option, users are allowed to view ACLs (with getfacl), but are not allowed to set them (with setfacl). This field provides host (the computer on which the file system is being mounted) identity information to the lock module. The format and behavior of HostIDInfo depends on the lock module used. For lock_gulm, it overrides the uname -n network node name used as the default value by lock_gulm. This field is ignored by the lock_dlm and lock_nolock lock modules. hostdata=HostIDInfo Forces GFS to treat the file system as a multihost file system. By default, using lock_nolock Caution: This option should not be used automatically turns on the localcaching and when GFS file systems are shared. localflocks flags. ignore_local_fs Tells GFS that it is running as a local file system. 19 Chapter 4. Managing GFS Option localcaching Description GFS can then turn on selected optimization capabilities that are not available when running in Caution: This option should not be used cluster mode. The localcaching flag is when GFS file systems are shared. [. . . ] To do this, no actual log directory is created; instead, an @hostname CDPN link is created with the name log. Individual directories /gfs/n01/, /gfs/n02/, and /gfs/n03/ are created that will be the actual directories used when each node references /gfs/log/. n01# cd /gfs n01# mkdir n01 n02 n03 n01# ln -s @hostname log n01# ls -l lrwxrwxrwx drwxr-xr-x drwxr-xr-x drwxr-xr-x /gfs 1 root 2 root 2 root 2 root root root root root 9 Apr 25 3864 Apr 3864 Apr 3864 Apr 14:04 log -> @hostname/ 25 14:05 n01/ 25 14:06 n02/ 25 14:06 n03/ n01# touch /gfs/log/fileA n02# touch /gfs/log/fileB n03# touch /gfs/log/fileC n01# ls /gfs/log/ fileA n02# ls /gfs/log/ fileB n03# ls /gfs/log/ fileC 42 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/cluster/cluster. conf) and convert GFS pool volumes to LVM2 volumes. This appendix contains instructions for upgrading from GFS 6. 0 (or GFS 5. 2. 1) to Red Hat GFS 6. 1, using GULM as the lock manager. Note You must retain GULM lock management for the upgrade to Red Hat GFS 6. 1; that is, you cannot change from GULM lock management to DLM lock management during the upgrade to Red Hat GFS 6. 1. [. . . ]