On Sep 12, 2008 10:17 +0200, Keld J�rn Simonsen wrote: > On Thu, Sep 11, 2008 at 03:07:01PM -0600, Andreas Dilger wrote: > > On Sep 11, 2008 07:43 +0200, Tobias Oetiker wrote: > > > Because if it is catastrophic, then it basically means that the > > > journal has to reside on a device that is as secure as to rest of > > > the data, meaning that if the data is on RAID6 then the journal > > > should be on RAID6 too. > > > > No, because RAID6 is terribly sucky for performance. If you need this > > kind of reliability triple-mirrored RAID 1 would be better. Much less > > CPU overhead, and no extra IO. > > RAID6 performs nicely for reads, but has quite bad performance for some > writes (non-sequential). Raid6 is actually surprisingly fast for > sequential reads. The journal is NEVER read during normal operation, only once during journal recovery after a crash. Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. _______________________________________________ Ext3-users mailing list Ext3-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/ext3-users
