Re: Horrible PostgreSQL performance with NFS
Arne Woerner <[email protected]>
| Newsgroups | gmane.os.freebsd.performance,gmane.os.freebsd.devel.database |
|---|---|
| Message-ID | <[email protected]> |
Hiho! --- Slawek Zak <[email protected]> wrote: > A couple of days ago I've moved our > production database from local disks > to NetAPP filer serving NFS. Performance > for this server dropped by factor of 10 > if not more. > I would like to suggest some tests (I do not have a clear idea, why your system becomes slower; a hypothesis will follow below): 1. benchmark the local disc (watch cpu usage via e. g. vmstat 1) % dd if=/dev/zero of=/some/local/filesystem/a bs=1m count=1000 2. benchmark the NFS filesystem (watch cpu usage via e. g. vmstat 1) % dd if=/dev/zero of=/some/NFS/filesystem/a bs=1m count=1000 3. test the NIC performance with (again watching the CPU usage might help) % ping -s 50000 <nfs-server> I get 17Mbit/sec which is the actual rate... neo# ping -s 50000 vaako PING vaako.riddick.homeunix.org (10.1.1.3): 50000 data bytes 50008 bytes from 10.1.1.3: icmp_seq=0 ttl=64 time=46.584 ms My theory would be, that your NICs need a lot of CPU time, while your local discs dont need so much CPU time. :-) Bye Arne __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-performance To unsubscribe, send any mail to "[email protected]"