bofh list wrote: > We are seeing some poor performance recently that is focused around > users with large mailboxes (100,000 message /INBOX, 80,000 message > subfolders, etc). > > The performance problem manifests as very high system% utilization - > basically iowait for NFS. > > There are two imap servers with plenty of horsepower/memory/etc. They > are connected to a 3050c cluster via gig-e. Here are the mount > options: > rw,tcp,nfsvers=3,rsize=8192,wsize=8192,nosuid,nodev,soft,intr,noac,actimeo=0 > > > I need to get this system% utilization brought down because it is > starting to slowdown imap performance for other users (it goes up to > 95% on a regular basis, with users that have folders with many > messages). > > My thought is to try removing the noac option and bump up the actimeo > value from 0 to 30. Unfortunately I don't have access to use a SLB to > direct traffic to individual servers. > > My understanding is that the worst that can happen is index corruption > (which will result in rebuilding them when it happens). > > Any thoughts? I'm running RC24. >
What operating system are you using? Performance over NFS is tremendously different. And each OS can be tweaked differently. You should try noatime (noxattr on solaris) regardless. Cheers
