Slow directory listings under light load
I have Debian Etch AMD64 installed on a Dell PowerEdge 1950, connected
to a MD1000 (SAS/SATA array) via a PERC5/e SAS controller. The array
is RAID5. The whole drive is LVM, 9TB are one big XFS partition.
Linear reads/writes are very fast, directory listings are also fast.
However, if the disk is under any kind of load (say someone
downloading a file at 20MB/s) long directory listings (ls -l) get
extremely slow. Listing a directory of 1000 files can take 5 minutes.
Normal directory listings remain reasonable.
If I strace ls -l, I notice its stopping at each getxattr() call for a
split second, seems that's where it is wasting all of its time.
Upon a recommendation at #xfs, I tried using attr2 via the mount
option. xfs_db -c version shows:
versionnum [0xb094+0x8] = V4,ATTR,ALIGN,DIRV2,EXTFLG,MOREBITS,ATTR2
The whole install is pretty vanilla. Any thoughts on why this system
can't handle this type of load? Please cc me as I am not subscribed to