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Each file in pnfs has a unique 12 byte long pnfsID. This is comparable to the inode number in other filesystems. The pnfsID used for a file will never be reused, even if the file is deleted. dCache uses the pnfsID for all internal references to a file.

The pnfsID of the file <filename> can be obtained by reading the command-file .(id)(<filename>) in the directory of the file.

A file in pnfs can be referred to by pnfsID for most operations. For example, the name of a file can be obtained from the pnfsID with the command nameof as follows:

[user] $ cd /pnfs/
[user] $ cat '.(nameof)(0004000000000000002320B8)'

And the pnfsID of the directory it resides in is obtained by:

[user] $ cat '.(parent)(0004000000000000002320B8)'

This way, the complete path of a file may be obtained starting from the pnfsID. Precisely this is done by the tool pathfinder:

[user] $ . /usr/etc/pnfsSetup
[user] $ PATH=$PATH:$pnfs/tools
[user] $ cd /pnfs/
[user] $ pathfinder 0004000000000000002320B8
0004000000000000002320B8 file.dat
0004000000000000001DC9E8 directory
000400000000000000001060 sub
000100000000000000001060 any
000000000000000000001080 usr
000000000000000000001040 fs
000000000000000000001020 root
000000000000000000001000 -
000000000000000000000100 -
000000000000000000000000 -

The first two lines configure the pnfs-tools correctly. The path obtained by pathfinder does not agree with the local path, since the latter depends on the mountpoint (in the example /pnfs/ The pnfsID corresponding to the mountpoint may be obtained with

[user] $ cat '.(get)(cursor)'

The dirID is the pnfsID of the current directory and mountID that of the mountpoint. In the example, the pnfs server path /root/fs/usr/ is mounted on /pnfs/