[LU-11306] Moving files from one MDT to another does not free inodes on source MDT

Related — Fri, 31 Aug 2018 16:48:16 +0000

When moving files that are on MDT0 to a directory residing on MDT1, the corresponding inodes on MDT are not deallocated.

Here is what I see:

[root@lustre211cli test]# for file in {1..999}; do echo $file > $file; done
[root@lustre211cli test]# lfs df -i
UUID                      Inodes       IUsed       IFree IUse% Mounted on
test-MDT0000_UUID         419432        1262      418170   1% /test[MDT:0]
test-MDT0001_UUID         419432         248      419184   1% /test[MDT:1]
test-OST0000_UUID         737280        1389      735891   0% /test[OST:0]

filesystem_summary:       737401        1510      735891   0% /test

[root@lustre211cli test]# lfs mkdir -i 1 dir2
[root@lustre211cli test]# mv {1..999} dir2/
[root@lustre211cli test]# lfs df -i
UUID                      Inodes       IUsed       IFree IUse% Mounted on
test-MDT0000_UUID         419432        1265      418167   1% /test[MDT:0]
test-MDT0001_UUID         419432        1249      418183   1% /test[MDT:1]
test-OST0000_UUID         737280        1389      735891   0% /test[OST:0]

filesystem_summary:       738405        2514      735891   0% /test

[root@lustre211cli test]# ls
dir1  dir2
[root@lustre211cli test]# ls dir1
[root@lustre211cli test]# sync
[root@lustre211cli test]# echo 3 > /proc/sys/vm/drop_caches
[root@lustre211cli test]# lfs df -i
UUID                      Inodes       IUsed       IFree IUse% Mounted on
test-MDT0000_UUID         419432        1265      418167   1% /test[MDT:0]
test-MDT0001_UUID         419432        1249      418183   1% /test[MDT:1]
test-OST0000_UUID         737280        1389      735891   0% /test[OST:0]

filesystem_summary:       738405        2514      735891   0% /test

The inodes used on MDT0 never decrease, even after umount/mount or by umounting the MDT from the MDS.

When performing an e2fsck (1.42.13.wc5) on MDT0, the behaviour changes between 2.10.4 and 2.11.54:

With 2.10.4, e2fsck will find as many unattached inodes as there were files moved
With 2.11.54, e2fsck will not find anything

I attach the complete debug logs from the client and server taken during this manipulation.

Whamcloud Community JIRA

[LU-11306] Moving files from one MDT to another does not free inodes on source MDT