Subject: FFS slowness
To: None <netbsd-users@netbsd.org>
From: Ivan Kanis <cake@tadpole.com>
List: netbsd-users
Date: 12/22/2005 16:03:14
Hello,
I am seeing poor performance with FFS + softdep.
My machine is an AMD Opteron and it is connected to a SCSI disk
with an Adaptec 7902 Ultra320 Wide card.
The problem in a nutshell is that I am getting 1/4 of the perfomance
when copying a directory compar to copying a big file.
For example copying the /usr directory:
amd64:/# time cp -r /usr /usr.bak
real 3m44.090s
user 0m0.144s
sys 0m2.884s
amd64:/# du -sh /usr
390M /usr
That's 1.7M/s
Copying a big ISO file:
amd64:/tmp# time cp big.iso big.iso.bak
real 1m37.254s
user 0m0.000s
sys 0m1.640s
amd64:/tmp# ls -lh big.iso
-rw-r--r-- 1 root wheel 635M Dec 22 15:18 big.iso
That's 6.6M/s
Since copying a single file is pretty fast it rules out an I/O problem
with the disk. Does anybody knows what causes the slowness? Any ideas
are welcome.
Thanks,
--
Ivan Kanis
Senior Software Developer
Tadpole Computer Limited
Tel: +44 (0) 870 432 4161
"Deep Hack Mode--that mysterious and frighteningstate of
consciousness where Mortal Users fear to tread."
-- Matt Welsh