My experience of the reclamation of off-site volumes doesn't quite match up
with my understanding of how it should work. Perhaps someone can shed some
light on what's really going on.

I'm starting reclamation at 10:00 by reducing the reclaim value from 100 to
50.
I run the following select statement to determine how many volumes are
eligible for reclamation at this time.

select count(volume_name) as "Number of vols" ,stgpool_name from volumes
where pct_reclaim>50
group by stgpool_name'

For my offsite pool I see there are 30  volumes which are truly offsite
which are eligible (and I also prepare a list of their volume_names).

(My expectation at this point is that a single process will run which will
reclaim ALL eligible volumes)

Time passes and at 16:00 the reclaim value is reset to 100. The reclaim
process faithfully continues its work which is to be expected. When it
finishes 3 hours later I expect to see that there are no eligible volumes
left. But in fact there are 8 eligible volumes (ie reclaim>50) which were
present in my morning list. The process has finished without reclaiming all
eligible volumes. And it wasn't cancelled.

Can anyone help explain what's going on here?

Regards,

Eric Winters


Joe Faracchio <brother AT SOCRATES.BERKELEY DOT EDU> on 14/03/2000 11:19:24

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

To:   ADSM-L AT VM.MARIST DOT EDU
cc:    (bcc: Eric Winters/Australia/Contr/IBM)
Subject:  Re: reclamation of off-site volumes




The behaviour I've seen says that it can go for a longer time than just
9-5 if you set the number too low or too "into" the chain. Especially if
the number chosen is not the tape with the most to be reclaimed.

I do :

   select volume_name,pct_reclaim,status,pct_utilized -
   from volumes where stgpool_name='COPYPOOL' -
   and pct_reclaim>$1 -
   order by pct_reclaim desc

where $1 is some number like 20 or 30  and then 'dive in' about 10 down.
The logic in ADSM causes all tapes down to this number to be reclamated
simultaneously.  If you TAPEPOOL is collocated then the offsite
reclamation should be more efficient read each onsite tape once to
reclamate the offsite information.

     joe.f.


Joseph A Faracchio, Systems Programmer, UC Berkeley
I

On Mon, 13 Mar 2000, Walter, Jeannine wrote:

> This is one of those duh questions but here goes anyway.
> I want to run reclamation of our off-site tapes during the day from 9AM
> until 4PM.  How do I do this?  By a script that runs as an admin
schedule?
> Anyone have a script they can share?
> Thanks.
>
> Regards,
> Jeannine Walter
>
> Purina Mills, Inc.
> St. Louis, MO
> 314-768-4181
> Jeannine_Walter AT Purina-Mills DOT com <mailto:Jeannine_Walter AT 
> Purina-Mills DOT com
>
>