Am 14.12.2010 um 03:30 schrieb Bob Friesenhahn <bfrie...@simple.dallas.tx.us>:
> On Mon, 13 Dec 2010, Stephan Budach wrote: >> >> My current run of bonnie is of course not that satisfactory and I wanted to >> ask you, if it's safe to turn on at least the drive level options, namely >> the write cache and the read ahead? > > Enabling the write cache is fine as long as it is non-volatile or is flushed > to disk when zfs requests it. Zfs will request a transaction-group flush on > all disks before proceeding with the next batch of writes. The read ahead > might not be all that valuable in practice (and might cause a severe penalty) > because it assumes a particular mode and timing of access which might not > match how your system is actually used. Most usage scenarios are something > other than what bonnie++ does. I know that bonnie++ does not generate the workload I will see on my server, but it reliably causes ZFS to kick out drives from the pool, which shouldn't happen, of course. Actually, I am expecting the Qsan controller fw, which is what is build into these raids, has some issues, when it has to deal with high random I/O. I will try now my good old Infortrend systems and See, if I can reproduce this issue with them as well. Cheers, Budy _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
