suddenly slow writes on XFS Filesystem

Stefan Priebe
2012-05-06T09:01:06Z

Hi,

since a few days i've experienced a really slow fs on one of our backup
systems.

I'm not sure whether this is XFS related or related to the Controller /
Disks.

It is a raid 10 of 20 SATA Disks and i can only write to them with about
700kb/s while doing random i/o. I tried vanilla Kernel 3.0.30 and 3.3.4
- no difference. Writing to another partition on another xfs array works
fine.

Details:
#~ df -h
/dev/sdb1 4,6T 4,4T 207G 96% /mnt

#~ df -i
/dev/sdb1 4875737052 4659318044 216419008 96% /mnt

#~ xfs_db -c frag -r /dev/sdb1
actual 83160469, ideal 82145389, fragmentation factor 1,22%

#~ xfs_info /dev/sdb1
meta-data=/dev/sdb1 isize=256 agcount=5,
agsize=268435392 blks
= sectsz=512 attr=2
data = bsize=4096 blocks=1218967031, imaxpct=5
= sunit=64 swidth=1280 blks
naming =version 2 bsize=4096 ascii-ci=0
log =internal bsize=4096 blocks=32768, version=2
= sectsz=512 sunit=64 blks, lazy-count=0
realtime =none extsz=4096 blocks=0, rtextents=0

#~ cat /proc/mounts
/dev/sdb1 /mnt xfs
rw,noatime,nodiratime,attr2,nobarrier,logbufs=8,logbsize=256k,sunit=512,swidth=10240,prjquota
0 0

Any ideas?

Stefan