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
