[zfs-discuss] Possible ZFS problem

andy thomas
Sat, 13 Aug 2011 07:25:16 -0000

We are using ZFS on a Sun E450 server (4 x 400 MHz CPU, 1 Gb memory, 18 Gb
system disk and 19 x 300 Gb disks running OSOL snv 134) for archive
storage where speed is not important. We have 2 RAID-Z1 pools of 8 disks
plus one spare disk shared between the two pools and this has apparently
worked well since it was set up several months ago.

However, one of our users recently put a 35 Gb tar.gz file on this server
and uncompressed it to a 215 Gb tar file. But when he tried to untar it,
after about 43 Gb had been extracted we noticed the disk usage reported by
df for that ZFS pool wasn''t changing much. Using du -sm on the
extracted
archive directory showed that the size would increase over a period of 30
seconds or so and then suddenly drop back about 50 Mb and start increasing
again. In other words it seems to be going into some sort of a loop and
all we could do was to kill tar and try again when exactly the same thing
happened after 43 Gb had been extracted.

Thinking the tar file could be corrupt, we sucessfully untarred the file
on a Linux system (1 Tb disk with plain ext3 filesystem). I suspect my
problem may be due to limited memory on this system but are there any
other things I should take into consideration? It''s not a major problem
as
the system is intended for storage and users are not supposed to go in and
untar huge tarfiles on it as it''s not a fast system ;-)

Andy

----------------------------
Andy Thomas,
Time Domain Systems

Tel: +44 (0)7866 556626
Fax: +44 (0)20 8372 2582