>The server originally was set up with a large enough DIRPOOL 
>of type DISK. Later, DIRPOOL was reduced in size, and a 
>DIRFILE stgpool was added that consists of FILE volumes. 
>Clients still back up to DIRPOOL, but that pool is migrated 
>daily to DIRFILE.
>
>Is this sort of setup still necessary with TSM 5.3 on AIX 5.2?
>I remember DIRFILE being set up because of performance 
>problems with offsite volume reclamation (mainly due to 
>sequential volumes being able to handle many files in one large chunk).

There was a problem at one time with offsite reclamation running slow
when reading from disk (this was fixed a couple of years ago).  If you
had a DIRPOOL of type DISK only you would have suffered a performance
problem.  Using FILE volumes would have fixed this.

>Also, ADSM.QuickFacts says that sequential volumes have 
>advantages in a database restoral situation.
Yes.  This is also documented in the 5.2/5.3 ADMIN guide describing
difference between DISK and FILE pools.

>Would it be a good idea to return to a large DIRPOOL of type 
>DISK and eliminate DIRFILE, on TSM 5.3 and AIX 5.2?
See above!

>>Storage pools that act as DIRMC management class destinations never
grow
>>to any size to speak of, and they contain redundant data; the normal
>>client data destination pool also contains a copy of all directory and
>>file structure data.

If you are using DIRMC to store your directories on a separate storage
pool then no, the normal client data destination pool does not contain
this data.

>>For multiple customers, I just set up a smallish disk-based storage
pool
>>from 5 to 7GB with cache turned on; once a week, a migration to the
>>regular primary tape pool takes place. Nothing fancy needed here.

This probably works because cache is turned on and there is enough space
on disk so that the tape pool is not needed when restoring/reclaiming
directories.

Note that if space were to run out here or if cache was not turned on
then directories end up on tape and lose the advantage of a DIR pool.
The biggest one to me is quick restores.  If directories are on tape
then you could have extra tape mounts/tape positioning for client
restores.  



--
Mark Stapleton (stapleton AT berbee DOT com)
Berbee Information Networks
Office 262.521.5627