On Sat, Apr 12, 2008 at 7:51 PM, Chris Siebenmann <[EMAIL PROTECTED]> wrote: > So, we are always going to have a certain number of logical pools of > storage space to manage. The question is whether to handle them as > separate ZFS pools or aggregate them into fewer ZFS pools and then > administer them as sub-hierarchies using quotas[*], and our current > belief is that doing the former is simpler to administer and simpler to > explain to users. I don't think that's the case. What's wrong with setting both a quota and a reservation on your user filesystems? What advantage will multiple zpools present over a single one with filesystems carved out of it? With a single pool, you can "expand" filesystems if the user requests it just by changing the quota and reservation for that filesystem, and add more capacity if necessary by adding more disks to the pool. If your policy is to use, say, a single pair of 35GB mirrors per zpool and the user wants more space, they need to split their files into categories somehow.
Also, you mention 'legacy' 35GB chunks that you can't give free upgrades to. A single-pool methodology will help with that - you can set arbitrary-sized quotas for whichever users want them. If one group wants to buy 10 gigs and another wants 47, you can give them exactly how much they want. Lastly, if you plan to support (or use internally) snapshots, a single large pool will be much easier to deal with. Taking snapshots and making large changes means that the snapshot starts taking up space, which could be problematic on a small pool. > [*: we've experimented, and quotas turn out to work better than reservations > for this purpose. You might want to use "refquota" and "refreservation" if you're running a Solaris that supports them---that precludes Solaris 10u4, unfortunately. If you're running Nevada, though, they're definitely the way to go. In any case, I'm interested in why multiple pools might be a good choice. We have a similar situation (albeit on a smaller scale) with many disks, a faculty member's data on each, and I'd like to start using ZFS for that. A single pool was the model that sprung to mind for the purpose, and I'd like to hear reasons why it might not be a good choice. Will _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
