Hey Peter, If I recall correctly, the result was there was a very slight space-efficiency benefit of using a multiple of 2 vdevs for raidz1 and of 3 vdevs for raidz2 -- doing this can reduce the number of 'skipped' blocks. That said, the advantage is very slight and is only really relevant when the blocksize or recordsize is relatively closer to the number of bytes in a stripe.
Adam On Thu, Jan 04, 2007 at 11:17:26PM +0000, Peter Tribble wrote: > I'm being a bit of a dunderhead at the moment and neither the site search > nor > google are picking up the information I seek... > > I'm setting up a thumper and I'm sure I recall some discussion of the > optimal > number of drives in raidz1 and raidz2 vdevs. I also recall that it was > something > like you would want an even number of disk for raidz1, and an odd number for > raidz2 (so you always have an odd number of data drives). Have I remembered > this correctly, or am I going delusional? And, if it is the case, what is > the > reasoning behind it? > > Thanks, > > -- > -Peter Tribble > http://www.petertribble.co.uk/ - http://ptribble.blogspot.com/ > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss -- Adam Leventhal, Solaris Kernel Development http://blogs.sun.com/ahl _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
