Robert Milkowski wrote: > Hello Bob, > > Friday, August 29, 2008, 7:25:14 PM, you wrote: > > BF> On Fri, 29 Aug 2008, Kyle McDonald wrote: >>> What would one look for to decide what vdev to place each LUN? >>> >>> All mine have the same Current Load Balance value: round robin. > > BF> That is a good question and I will have to remind myself of the > BF> answer. The "round robin" is good because that means that there are > BF> two working paths to the device. There are two "Access State:" lines > > > Assuming that you have only two paths and each one connected to > different controller you will be using only one path for each LUN as > 25x0 is an asymmetric disk array. > > Sometimes people tend to create several luns and assign some of them > to one controller and some of them to another one. Now if you do > striping or raid-10 between these luns you will end-up using both > controllers which will improve performance for some workloads. > > The drawback is that in case one controller fails you may expect > performance degradation.
And sometimes that failover can happen at the most inconvenient moment, too. Another reason why I prefer active-active arrays :) (Just wish I could afford one for home use!) Still, if you're using MPxIO that failover shouldn't be a problem. James C. McPherson -- Senior Kernel Software Engineer, Solaris Sun Microsystems http://blogs.sun.com/jmcp http://www.jmcp.homeunix.com/blog _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
