On Sat, Mar 28, 2009 at 11:06 AM, Michael Shadle <mike...@gmail.com> wrote: > On Sat, Mar 28, 2009 at 1:37 AM, Peter Tribble <peter.trib...@gmail.com> > wrote: > >> zpool add tank raidz1 disk_1 disk_2 disk_3 ... >> >> (The syntax is just like creating a pool, only with add instead of create.) > > so I can add individual disks to the existing tank zpool anytime i want?
Yes, but you wouldn't want to do that. (And zpool might not like it.) If you just add a disk, it just gets added as a new device. So you have unprotected storage. In particular, you can't grow the existing raidz. What you're doing here is adding a second raidz1 vdev. That's good because the 2nd phase of your storage is just like the first phase. >> It makes perfect sense. My thumpers have a number of raidz vdevs combined >> into a single pool. Your performance scales with the number of vdevs, and >> its better to combine them into a single pool as you combine the performance. >> Generally, unless you want different behaviour from different pools, it's >> easier >> to combine them. > > so essentially you're tleling me to keep it at raidz1 (not raidz2 as > many people usually stress when getting up to a certain # of disks, > like 8 or so most people start bringing it up a lot) The choice of raidz1 versus raidz2 is another matter. Given that you've already got raidz1, and you can't (yet) grow that or expand it to raidz2, then there doesn't seem to be much point to having the second half of your storage being more protected. If you were starting from scratch, then you have a choice between a single raidz2 vdev and a pair of raidz1 vdevs. (Lots of other choices too, but that is really what you're asking here I guess.) With 1.5T drives, I would want a second layer of protection. If you didn't have backups (by which I mean an independent copy of your important data) then raidz2 is strongly indicated. I have a thumper that's a primary fileserver. It has a single pool that is made up of a number of raidz2 vdevs. I'm replacing it with a pair of machines (this gives me system redundancy as well); each one will have a number of raidz1 vdevs because I can always get the data back off the other machine if something goes wrong. -- -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
