Constantin Gonzalez wrote: > Hi, > > >> I'm quite interested in ZFS, like everybody else I suppose, and am about >> to install FBSD with ZFS. >> > > welcome to ZFS! > > >> Anyway, back to business :) >> I have a whole bunch of different sized disks/speeds. E.g. 3 300GB disks >> @ 40mb, a 320GB disk @ 60mb/s, 3 120gb disks @ 50mb/s and so on. >> >> Raid-Z and ZFS claims to be uber scalable and all that, but would it >> 'just work' with a setup like that too? >> > > Yes. If you dump a set of variable-size disks into a mirror or RAID-Z > configuration, you'll get the same result as if you had the smallest of > their sizes. Then, the pool will grow when exchanging smaller disks with > larger. > > I used to run a ZFS pool on 1x250GB, 1x200GB, 1x85 GB and 1x80 GB the > following > way: > > - Set up an 80 GB slice on all 4 disks and make a 4 disk RAID-Z vdev > - Set up a 5 GB slice on the 250, 200 and 85 GB disks and make a 3 disk RAID-Z > - Set up a 115GB slice on the 200 and the 250 GB disk and make a 2 disk > mirror. > - Concatenate all 3 vdevs into one pool. (You need zpool add -f for that). > > Not something to be done on a professional production system, but it worked > for my home setup just fine. The remaining 50GB from the 250GB drive then > went into a scratch pool. > > Kinda like playing Tetris with RAID-Z... > > Later, I decided using just paired disks as mirrors are really more > flexible and easier to expand, since disk space is cheap. > >
well i'm about to go read the entire admin manual now that I found it and I hope it will explain all my further questions, but before i start doing so, How are paired mirrors more flexiable? Right now, i have a 3 disk raid 5 running with the linux DM driver. One of the most resent additions was raid5 expansion, so i could pop in a matching disk, and expand my raid5 to 4 disks instead of 3 (which is always interesting as your cutting on your parity loss). I think though in raid5 you shouldn't put more then 6 - 8 disks afaik, so I wouldn't be expanding this enlessly. So how would this translate to ZFS? I have learned so far that, ZFS basically is raid + LVM. e.g. the mirrored raid-z pairs go into the pool, just like one would use LVM to bind all the raid pairs. The difference being I suppose, that you can't use a zfs mirror/raid-z without having a pool to use it from? Wondering now is if I can simply add a new disk to my raid-z and have it 'just work', e.g. the raid-z would be expanded to use the new disk(partition of matching size) > Hope this helps, > Constantin > > Thanks, Oliver _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
