On Tue, eric kustarz wrote: > Ben Rockwood wrote: > >I was really hoping for some option other than ZIL_DISABLE, but finally > >gave up the fight. Some people suggested NFSv4 helping over NFSv3 but it > >didn't... at least not enough to matter. > > > >ZIL_DISABLE was the solution, sadly. I'm running B43/X86 and hoping to > >get up to 48 or so soonish (I BFU'd it straight to B48 last night and > >brick'ed it). > > > >Here are the times. This is an untar (gtar xfj) of SIDEkick > >(http://www.cuddletech.com/blog/pivot/entry.php?id=491) on NFSv4 on a 20TB > >RAIDZ2 ZFS Pool: > > > >ZIL Enabled: > >real 1m26.941s > > > >ZIL Disabled: > >real 0m5.789s > > > > > >I'll update this post again when I finally get B48 or newer on the system > >and try it. Thanks to everyone for their suggestions. > > > > I imagine what's happening is that tar is a single-threaded application > and it's basically doing: open, asynchronous write, close. This will go > really fast locally. But for NFS due to the way it does cache > consistency, on CLOSE, it must make sure that the writes are on stable > storage, so it does a COMMIT, which basically turns your asynchronous > write into a synchronous write. Which means you basically have a > single-threaded app doing synchronous writes- ~ 1/2 disk rotational > latency per write. > > Check out 'mount_nfs(1M)' and the 'nocto' option. It might be ok for > you to relax the cache consistency for client's mount as you untar the > file(s). Then remount w/out the 'nocto' option once you're done.
This will not correct the problem because tar is extracting and therefore creating files and directories; those creates will be synchronous at the NFS server and there is no method to change this behavior at the client. Spencer > > Another option is to run multiple untars together. I'm guessing that > you've got I/O to spare from ZFS's point of view. > > eric > > _______________________________________________ > 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
