ADSM-L

Re: Multiple fillings per node with collocate is group

2005-09-08 11:13:23
Subject: Re: Multiple fillings per node with collocate is group
From: Maurice van 't Loo <tsm AT COMPARECOMPUTERS DOT NL>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Thu, 8 Sep 2005 17:13:07 +0200
Aaahhh.... That could be the reason......
I can see clearly now :-)

Thanks,
Maurice

----- Original Message -----
From: "Jim Armstrong" <jim_armstrong AT STANDARDLIFE DOT COM>
To: <ADSM-L AT VM.MARIST DOT EDU>
Sent: Thursday, September 08, 2005 2:36 PM
Subject: Re: [ADSM-L] Multiple fillings per node with collocate is group


> My understanding is that if TSM is busy dismounting a tape, then gets a
> request to migrate more data to that node, it will call for a new scratch
> tape, even if the tape it is busy dismounting is not full. The logic is
> that it is faster to mount a fresh scratch tape than wait for the tape
that
> is being dismounted to be returned to its library slot then remounted
> again. As you are running migration alongside backups I can see how this
> can happen on a frequent basis.
>
>
>   |     Subject:    Re: Multiple fillings per node with collocate is group
|
>
>---------------------------------------------------------------------------
------------------------------------|
>
>
>
>
> From: "Andrew Raibeck" <storman AT US.IBM DOT COM>
>
>
> > What is the storage pool's COLLOCATE value set to?
> Collocate = Group
>
> From: "Thorneycroft, Doug" <dthorneycroft AT LACSD DOT ORG>
>
> >Are there also backups running during this period, If the diskpool
doesn't
> >have enough space, or a client has files that exceed the diskpools
> >maxsize then some of your backups could be using the extra tapes.
>
> Backups are running during the whole day, also during migration. And we
> migrate (automaticly) during backup.
> There is enough space, hi=50%, lo=10%, size=2400GB, we don't get above the

> 80% during the top backups.
> There is no maxsize threshold defined.
>
> From: "Volker Maibaum" <volker.maibaum AT EBERSPAECHER DOT COM>
>
> > I don't think that TSM uses only 1 tape per collocgroup when you have
> > set maxpr=3. What if only data of one collocgroup is on the diskpool?
> > TSM would waste resources.
> > If you turn collocation=none for the tape pool than TSM also uses three

> > tapes at a time.
>
> The doc's said that when a migrate starts, it selects a node or group to
> migrate (with biggest FS or biggest node in case of colloc.groups) and
does
> the migration in 1 stream, so it "must" always use 1 tape at the time.
(see
> page 259 in 5.3 Admin Guide)
>
> --------------------------------------------------------------------------
--
>
> ---
> -----Original Message-----
> From: Maurice van 't Loo
> Sent: Tuesday, September 06, 2005 11:38 PM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: Multiple fillings per node with collocate is group
>
>
> Hi *SM'ers
>
> After migration from diskpool to tapepool, we see every day that several
> nodes or collocation groups have 2 or sometimes even 3 filling tapes.
>
> As far as i know, migration is always 1 stream per node/collocgroup, so
> there must be only 1 filling max.
> Right?
> Is this a bug, a feature or misunderstanding??
>
> Tapepool: 3584 libr. with 5 drives
> Migration: hi=50 lo=10 maxpr=3
> Server 5.3.1.2 @ aix
>
> Regards,
> Maurice van 't Loo
>
>
>
>
>
>
> For more information on Standard Life, visit our website
> http://www.standardlife.co.uk/
>
> The Standard Life Assurance Company, Standard Life House, 30 Lothian Road,
> Edinburgh EH1 2DH, is registered in Scotland (No. SZ4) and is authorised
> and regulated by the Financial Services Authority. Tel: 0131 225 2552 -
> calls may be recorded or monitored. This confidential e-mail is for the
> addressee only. If received in error, do not retain/copy/disclose it
> without our consent and please return it to us. We virus scan and monitor
> all e-mails but are not responsible for any damage caused by a virus or
> alteration by a third party after it is sent.
>

<Prev in Thread] Current Thread [Next in Thread>