On January 24, 2010 8:26:07 AM -0800 "R.G. Keen" <k...@geofex.com> wrote:
“Fewer/bigger versus more/smaller drives”: Tim and Frank have worked this one over. I made the choice based on wanting to get a raidz3 setup, for which more disks are needed than raidz or raidz2. This idea comes out of the time-to-resilver versus time to failure line of reasoning.
Sorry I missed this part of your post before responding just a moment ago. If you want raidz3, you will spend more money on larger drives if your data still fits into N smaller drives. If you only have .75TB of data, then of course it is a waste to get 1.5TB drives because you still need 5 (1+3)+1 of them and you should definitely use the cheaper .75TB drives. But you'd do even better to use a triple mirror of the smaller drives. Once the size of your data exceeds the size of the smaller drive, and you have to buy 2 of them just for the data part (not incl. the parity), it's now more expensive to use the smaller drives. In the above paragraph you haven't mentioned cost at all, but since you did talk elsewhere about the cost of the smaller drives being cheaper, I wanted to make it clear you are spending more money by using the smaller drives. -frank _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
