On Sat, May 05, 2007 at 02:41:28AM -0700, Christian Rost wrote: > > - Buying "cheap" 8x250 GB SATA disks at first and replacing them from time to > time by 750 GB > or bigger disks. Disadvantage: At the end i've bought 8x250 GB + 8x750 GB > Harddisks.
Look at it this way. The amount you spend on 750G disks now will be equal to the amount yould would spend on 250G now and 750G later after the prices drop. For the same cost of what you would spend on 750G disks now, you would end up with a set of both 250G *AND* 750G disks. Maybe those 250G disks can be used elsewhere. Maybe buying more controllers and more disk enclosures and *ADDING* the 750G disks to the pool would be something of a reasonable cost in the future. then you would essenially have 1TB disks worth of space. THe beauty of ZFS (IMHO) is that you only need to keep disks the same size within a vdev, not the pool. so a raidz vdev of 250G disks and a raidz vdev of 750G disks will happily work in a single pool. To showcase ZFS at work i setup a zpool with three vdevs. Two 146G disks in a mirror, 5 36G disks in a raidz and 5 76G disks in a raidz. Everyone was completely impressed. ;) -brian ps: does mixing raidz and mirrors in a single pool have any performance degradation associated with it? Is ZFS smart enough to know what the read/write characteristics of a mirror vs. a raidz and try to take advantage of that? Just curious. -- "Perl can be fast and elegant as much as J2EE can be fast and elegant. In the hands of a skilled artisan, it can and does happen; it's just that most of the shit out there is built by people who'd be better suited to making sure that my burger is cooked thoroughly." -- Jonathan Patschke _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
