This is a Windows box, not a DB that flushes every write. The drives are capable of over 2000 IOPS (albeit with high latency as its NCQ that gets you there) which would mean, even with sync flushes, 8-9MB/sec.
-marc On 2/10/10, Brent Jones <br...@servuhome.net> wrote: > On Wed, Feb 10, 2010 at 3:12 PM, Marc Nicholas <geekyth...@gmail.com> wrote: >> How does lowering the flush interval help? If he can't ingress data >> fast enough, faster flushing is a Bad Thibg(tm). >> >> -marc >> >> On 2/10/10, Kjetil Torgrim Homme <kjeti...@linpro.no> wrote: >>> Bob Friesenhahn <bfrie...@simple.dallas.tx.us> writes: >>>> On Wed, 10 Feb 2010, Frank Cusack wrote: >>>> >>>> The other three commonly mentioned issues are: >>>> >>>> - Disable the naggle algorithm on the windows clients. >>> >>> for iSCSI? shouldn't be necessary. >>> >>>> - Set the volume block size so that it matches the client filesystem >>>> block size (default is 128K!). >>> >>> default for a zvol is 8 KiB. >>> >>>> - Check for an abnormally slow disk drive using 'iostat -xe'. >>> >>> his problem is "lazy" ZFS, notice how it gathers up data for 15 seconds >>> before flushing the data to disk. tweaking the flush interval down >>> might help. >>> >>>>> An "iostat -xndz 1" readout of the "%b% coloum during a file copy to >>>>> the LUN shows maybe 10-15 seconds of %b at 0 for all disks, then 1-2 >>>>> seconds of 100, and repeats. >>> >>> what are the other values? ie., number of ops and actual amount of data >>> read/written. >>> >>> -- >>> Kjetil T. Homme >>> Redpill Linpro AS - Changing the game >>> >>> _______________________________________________ >>> zfs-discuss mailing list >>> zfs-discuss@opensolaris.org >>> http://mail.opensolaris.org/mailman/listinfo/zfs-discuss >>> >> >> -- >> Sent from my mobile device >> _______________________________________________ >> zfs-discuss mailing list >> zfs-discuss@opensolaris.org >> http://mail.opensolaris.org/mailman/listinfo/zfs-discuss >> > > ZIL performance issues? Is writecache enabled on the LUNs? > > -- > Brent Jones > br...@servuhome.net > -- Sent from my mobile device _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
