On Mon, 21 Jun 2010, Arne Jansen wrote:
Especially if the characteristics are different I find it a good idea to mix all on one set of spindles. This way you have lots of spindles for fast access and lots of space for the sake of space. If you devide the available spindles in two sets you will have much fewer spindles available for the responsiveness goal. I don't think taking them into a mirror can compensate that.
This is something that I can agree with. Total vdevs in the pool is what primarily determines its responsiveness. while using the same number of devices, splitting the pool might not result in more vdevs in either pool. Mirrors do double the amount of readable devices but the side selected to read is random so the actual read performance improvement is perhaps on the order of 50% rather than 100%. Raidz does steal IOPS so smaller raidz vdevs will help and result in more vdevs in the pool.
Bob -- Bob Friesenhahn bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
