[Lustre-discuss] Unbalanced OST--for discussion purposes

[Ms. Megan Larko]

Hi,

I have a Lustre array (version  2.6.18-53.1.13.el5_lustre.1.6.4.3smp)
which will soon be decommissioned in favor of newer hardware.
Therefore this question is mostly for my personal intellectual
curiosity.

I logged directly into the OSS (OSS4) and just ran a df (along with a
periodic check of the log files).  I last looked about two weeks ago
(I know it was after 17 Feb).   Anyway, the OST0007 is more full than
any of the other OSTs.  The default lustre stripe (I believe that is
set to 1) is used.    Can just one file shift the size used of one OST
that significantly?  What other reasonable explanation for a
difference on one OST in comparison with the others?  Could this cause
a lustre performance hit at this point?

   [root at oss4 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on

/dev/sdb1             6.3T  3.6T  2.5T  60% /srv/lustre/OST/crew8-OST0000
/dev/sdb2             6.3T  4.1T  1.9T  69% /srv/lustre/OST/crew8-OST0001
/dev/sdc1             6.3T  3.3T  2.8T  55% /srv/lustre/OST/crew8-OST0002
/dev/sdc2             6.3T  3.3T  2.7T  56% /srv/lustre/OST/crew8-OST0003
/dev/sdd1             6.3T  3.5T  2.6T  58% /srv/lustre/OST/crew8-OST0004
/dev/sdd2             6.3T  4.1T  1.9T  69% /srv/lustre/OST/crew8-OST0005
/dev/sdi1             6.3T  3.9T  2.2T  65% /srv/lustre/OST/crew8-OST0006
/dev/sdi2             6.3T  5.0T 1015G  84%
/srv/lustre/OST/crew8-OST0007     <----
/dev/sdj1             6.3T  3.4T  2.7T  56% /srv/lustre/OST/crew8-OST0008
/dev/sdj2             6.3T  3.3T  2.7T  56% /srv/lustre/OST/crew8-OST0009
/dev/sdk1             6.3T  3.4T  2.7T  56% /srv/lustre/OST/crew8-OST0010
/dev/sdk2             6.3T  3.8T  2.2T  64% /srv/lustre/OST/crew8-OST0011

Still learning....
megan