When you say rewrites, can you give more detail? For example, are you rewriting in 8K chunks, random sizes, etc? The reason I ask is because ZFS will, by default, use 128K blocks for large files. If you then rewrite a small chunk at a time, ZFS is forced to read 128K, modify the small chunk you're changing, and then write 128K. Obviously, this has adverse effects on performance. :) If your typical workload has a preferred block size that it uses, you might try setting the recordsize property in ZFS to match - that should help.
If you're completely rewriting the file, then I can't imagine why it would be slow. The only thing I can think of is the forced sync that NFS does on a file closed. But if you set zil_disable in /etc/system and reboot, you shouldn't see poor performance in that case. Other folks have had good success with NFS/ZFS performance (while other have not). If it's possible, could you characterize your workload in a bit more detail? --Bill On Fri, Apr 20, 2007 at 04:07:44PM -0400, Andy Lubel wrote: > > We are having a really tough time accepting the performance with ZFS > and NFS interaction. I have tried so many different ways trying to > make it work (even zfs set:zil_disable 1) and I'm still no where near > the performance of using a standard NFS mounted UFS filesystem - > insanely slow; especially on file rewrites. > > We have been combing the message boards and it looks like there was a > lot of talk about this interaction of zfs+nfs back in november and > before but since i have not seen much. It seems the only fix up to > that date was to disable zil, is that still the case? Did anyone ever > get closure on this? > > We are running solaris 10 (SPARC) .latest patched 11/06 release > connecting directly via FC to a 6120 with 2 raid 5 volumes over a bge > interface (gigabit). tried raidz, mirror and stripe with no > negligible difference in speed. the clients connecting to this > machine are HP-UX 11i and OS X 10.4.9 and they both have corresponding > performance characteristics. > > Any insight would be appreciated - we really like zfs compared to any > filesystem we have EVER worked on and dont want to revert if at all > possible! > > > TIA, > > Andy Lubel > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
