The Gfs Withdraw Function; Cdpn Variable Values - Red Hat ENTERPRISE LINUX 5 - GLOBAL FILE SYSTEM Manual

Variable
@os
@sys
@uid
@gid
Table 3.5. CDPN Variable Values
Example
In this example, there are three nodes with hostnames n01, n02 and n03. Applications on each node
uses directory /gfs/log/, but the administrator wants these directories to be separate for each
node. 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 /gfs
lrwxrwxrwx 1 root root 9 Apr 25 14:04 log -> @hostname/
drwxr-xr-x 2 root root 3864 Apr 25 14:05 n01/
drwxr-xr-x 2 root root 3864 Apr 25 14:06 n02/
drwxr-xr-x 2 root root 3864 Apr 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

3.16. The GFS Withdraw Function

The GFS withdraw function is a data integrity feature of GFS file systems in a cluster. If the GFS
kernel module detects an inconsistency in a GFS file system following an I/O operation, the file system
becomes unavailable to the cluster. The I/O operation stops and the system waits for further I/O
operations to error out, preventing further damage. When this occurs, you can stop any other services
or applications manually, after which you can reboot and remount the GFS file system to replay the
journals. If the problem persists, you can unmount the file system from all nodes in the cluster and
Description
This variable resolves to a real file or directory named with the
operating-system name string produced by the output of the following
command: echo `uname -s`
This variable resolves to a real file or directory named with the
combined machine type and OS release strings produced by the
output of the following command: echo `uname -m`_`uname -s`
This variable resolves to a real file or directory named with the user ID
string produced by the output of the following command: echo `id -
u`
This variable resolves to a real file or directory named with the group
ID string produced by the output of the following command: echo `id
-g`
Example
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