Someone else replied to me and said that if the disk pool is quite full
because migration has only just started and a backup tries to back up a
large file, the backup could try and write the file directly to tape.
This made sense because I could only see one migration process happening
at the time.
To try and avoid this in future, I have reduced the High Migration
threshold on disk to 80%.

Dianne Sharp
Operations Analyst
ISS CUSTOMER SUPPORT
Ext 4208

>----------
>From:  Marcos A. Morelatto[SMTP:FY010 AT DBMAIL.DEBIS DOT DE]
>Sent:  Saturday, 28 December, 1996 1:28AM
>To:    Multiple recipients of list ADSM-L
>Subject:       Cartridge driv
>
>--- Recebido de   F195.FY099  0055 11 886 2827      27/12/96 09.29
>
>  -> DBMAIL.INTERNET       LOTUS NOTES OTTOBRUNN
>
> Dianne,
>
> look at the value in the "migration processes" field of your dasd storage
> pool. In owr MVS ADSM Server (V1.2.04) we use this to quickly cleanup,
> with four migration tasks, owr dasd storage pool.
>
> Regards,
> Marcos A. Morelatto
>
> HUMAITA - Informatica e Tecnologia
> (A Mercedes-Benz of Brazil Company)
>
>
>
>
>We are running ADSM Server V1 on MVS and it appears that sometimes when
>a Migration process starts, it uses 2 cartridge drives simultaneously.
>I can't seem to find anything in the manuals about how to control this.
>Can someone please help me?
>
>Dianne Sharp
>Operations Analyst
>ISS CUSTOMER SUPPORT
>Ext 4208
>
>