On July 8, Bill Lancaster wrote :

[Lots of very, very valuable stuff deleted]

> A couple of rules of thumb we followed:
>
> 1.  Don't mix unlike-size drives on a single volume set.  This is mostly an
> operational consideration.  We wanted to avoid having the small volumes in
> the set fill up first with plenty of space left on the larger volumes.

[More good stuff deleted]

MPE SSM (Secondary Storage Manager) module is supposed to fill volumes in
terms of percentage, not absolute value, so it should not be a problem, as
occupation percentages should be roughly similar ... to some extent, that is.
SSM internals provides for checks to ensure that a given volume always has
some free space. That is especially true for system disks. Degraded mode is
expressed as a percentage of system disks occupation, critical mode is in
absolute value, a very low value indeed .

Just my $.02 ...

Christian Lheureux
Independent Consultant