There is probably not a short answer to this one. We use Q-trees to manage all of our data so that we get some virtualization of our storage, but we break up data into volumes based on how the data is used. For instance we have our Oracle databases on our filers. In that environment, we have a separate volume for each of the following: tables, logs, and archives. The reason for this is that we use snapshots for backups and data replication. If we have table, logs, and archives in the same volume, a snapshot would take a point in time image of all of the data at the same time, but we actually need to snapshot the archives separately for recoverability. Additionally, we can lose any one entire volume and still recover our data without risking corruption.

If you are just using this for plain ol' files, you probably can get away with putting everything into one volume. If it is critical data you may want to snap mirror the critical data so that the critical data is not at risk.

>>> Steve Vawter <svawter@c-cube.com> 02/21/01 05:50PM >>>
Having a set of Filers that have been poorly planned and poorly configured,
I would ask for a hand from fellow admins about how to proceed.
(okay, I know the best way, buy a new cluster of 840's and migrate it all!)

Given that I have 12 "36GB" disks (plus a hot spare) that have been
added to one of my filers, should I:

a) Build one large volume and control it's space via qtrees?
    a1) If so, should I lower the raidgroup size or leave it at 14?
b) Build multiple (2? 3? 4?) volumes of smaller size

Pro's & Con's for each approach would be greatly appreciated!

Steve Vawter     voice: 408-490-5310    fax: 408-490-8615
Staff UNIX Systems Administrator    Steve.Vawter@C-Cube.COM