Installation guide

Values”) to represent one of multiple existing files or directories. This string is not the name

of an actual file or directory itself. (The real files or directories must be created in a separate

step using names that correlate with the type of variable used.)

LinkName

Specifies a name that will be seen and used by applications and will be followed to get to

one of the multiple real files or directories. When LinkName is followed, the destination de-

pends on the type of variable and the node or user doing the following.

Variable Description

@hostname This variable resolves to a real file or directory named with the

hostname string produced by the output of the following command:

echo `uname -n`

@mach This variable resolves to a real file or directory name with the ma-

chine-type string produced by the output of the following com-

mand: echo `uname -m`

@os This variable resolves to a real file or directory named with the op-

erating-system name string produced by the output of the following

command: echo `uname -s`

@sys 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`

@uid 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`

@gid 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`

Table 4.5. 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 cre-

ated 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/

Example