From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On 
Behalf Of Jurjen Oskam
>I have a question about which devclass to use for a 
>storagepool that is exclusively used as DIRMC destination.
>
>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).
>
>Also, ADSM.QuickFacts says that sequential volumes have 
>advantages in a database restoral situation.
>
>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?

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.

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.

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