We have hi and lo thresholds fairly close together: 85% and 75%. That way,
if migration does occur, it will not flush out too much data from the disk
pool. In that way, when we perform a copy storage pool, most of the data
will be taken from disk, which is a whole lot faster than tape-to-tape.

Dan Giles
Application Specialist
Manulife Financial, Corporate
Phone: 416-926-3549 Fax: 416-926-5234





From: "Mauro M. TINELLI" <Mauro.TINELLI AT ST DOT COM> on 99/01/21 08:45 AM GMT

Please respond to "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>

To:   ADSM-L AT VM.MARIST DOT EDU
cc:    (bcc: ADSM)
Subject:  Re: ADSM Performance Question




Jawad,

        these're my experience and feelings ...

1) Migration processes are always cuncurrent. For quicker migration you
   can spawn more than one process.

2) I would use a higher 'lowmig' say 10%. 0% may lead to a situation
   were the migration process never stop, or some deadlock.

Ciao Mauro

> Hello, i am using ADSM 3.1.2.1 with AIX 4.3.2. I have 10 GB of SSA
> configured as a diskpool and a 7337 DLT configured as a tapepool. I
have
> set the migration limits for diskpool as follows
>
> highmig 90
> lowmig 0
>
> What happens when the migration process starts on the diskpool. Do the
> files stop getting backed up for the period the migration is taking
> place or do the two processes happen concurrently( i.e backup to
> diskpool and migration from diskpool)?.
>
> If the former, is it better to use a very small diskpool, so in effect
> the data streams almost directly to the tape device?
>
> Thanks in advance
>
> Jawad Khayyam Butt
>
> Senior Integration Specialist
> GE Capital IT Solutions
> 5985 Mclaughlin Road, Mississauga, ON L5R 1B8
>
> Tel: 905-568-9707x7151     Email: jbutt AT gects.ge DOT com