Retrieving the Number of Hard Links

Explains how to retrieve the number of hard links to a file.

To retrieve the number of hard links associated with a file, run the following command:

ls -l

The command, ls -l, will print the number of hardlinks in the second column. For example, your output will look similar to the following:

ls -l sample-link
  rw-r--r- 2 root root 0 Apr 21 11:09 sample-link

To retrieve the list of the hard links associated with a file, run the following command:

find <dirpath> -samefile <sourcefile>

where <dirpath> is the path to the source file and <sourcefile> is the source file for the hard link. For example, your output will look similar to the following:

find . -samefile file8
  ./file8-link2
  ./file8-link100
  ./file8-link101
  ./file8
  ./file8-link

For POSIX (loopback NFS for the HPE Ezmeral Data Fabric) clients, the number of hardlinks to a file can be retrieved using the stat64 system call. For example, your output will look similar to the following:

stat samplefile
  File: 'samplefile'
  Size: 0               Blocks: 0          IO Block: 131072 regular empty file
  Device: 14h/20d Inode: 853785146   Links: 4
  Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (    0/    root)
  Access: 2016-05-12 13:06:21.000000000 -0700
  Modify: 2016-05-12 13:06:30.002560000 -0700
  Change: 2016-05-12 13:06:30.002560000 -0700

If you are not using NFS for the HPE Ezmeral Data Fabric or the POSIX clients, to retrieve the number of hard links, you can run the hadoop command to retrieve the fid and then run the maprcli command to retrieve the number of hard links as follows. The nlink variable will print the number of links.

hadoop mfs -ls /p1
  Found 1 items
  -rw-r--r--  Z U U   3 root root       3054 2016-05-05 13:49  268435456 /p1
  p 2049.40.262550  node-31.lab:5660

maprcli fid stat -fid 2049.40.262550
  xattrInum  uid  atime       nblocks  deleteFlags     mtime       parent     nlink  type       version  size  mode  networkencryption  subtype   gid  compression  
  0          0    1462481255  1        DeleteTypeNone  1462481376  2049.16.2  2      FTRegular  2097165  3054  644   false              FSTInval  0    lz4