Hehe, just as a thought experiment...

Presuming our instances are of equal size, they would be equally running
jobs at the same times.  So they would all equally have a couple drives
available to be pre-empted.

In reality, our instances are not equal in size and it is the large ones
that would tend to have jobs running during the day.  (Smaller instances
finish by 7am)
But also, since they are large, they are also more likely have the data
someone would want restored.  Which means they would also have drives
available to be pre-empted.

I supposed I'm a TSM geek since I think this is fun!

Regards,
Shawn
________________________________________________
Shawn Drew




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Sent by: ADSM-L AT VM.MARIST DOT EDU
09/22/2009 02:17 PM
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Re: [ADSM-L] Limiting number of drives used






I _Almost_ agree with Kelly. A restore will preempt any process
running on the same server, but with 6 TSM instances, chances are that
your restore is running on a TSM instance that has nothing to preempt,
while other instances are busy with eg. reclamation or other less
essential tasks.

On 22 sep 2009, at 19:58, Shawn Drew wrote:

> HA, perfect!  I never knew about the AUTOLABEL option.    And
> wouldn't you
> know it, we have it enabled already.
> I also just found out about "SET DRMCHECKLABEL".  I think that will
> take
> care of everything.
>
> I don't have any useful counter ideas but I did have a thought: why
> limit
> it?  You can set the library to autolabel tapes so you don't need to
> do
> that as a separate function and a restore can pre-empt anything
> running
> (except a DB backup). You will wait a couple of minutes while the tape
> dismounts and mounts.
>
> I guess when one has 18 tape drives having two on the sideline
> waiting to
> do something isn't a bad idea.  18 tape drives!  And they're
> probably the
> big fast expensive ones too, aren't they?
>
> Kelly Lipp
> Chief Technical Officer
> www.storserver.com
> 719-266-8777 x7105
> STORServer solves your data backup challenges.
> Once and for all.
>
>
> -----Original Message-----
> From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On
> Behalf Of
> Shawn Drew
> Sent: Tuesday, September 22, 2009 10:03 AM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: [ADSM-L] Limiting number of drives used
>
> I would like to keep 2 drives unused at all times for restores and
> labeling scratch tapes.
>
> TSM 5.5/AIX/Atape
> We have 18 Drives, 1 library manager and 5 library clients.
>
> The "classic" method is to set the "Mount limit" in the device class.
> However, we also have NDMP clients which are configured so there is
> more
> than one device class pointing to the same library.
>
> - I can't limit the NAS and LTO device classes each to 16 Drives
> because
> some of the time, jobs to both device classes will be running at the
> same
> time so the individual classes won't reach 16.
> - I can't limit each to 8, because the NDMP jobs definitely need
> more than
> 8 drives when they are running at night, and the other device class
> needs
> more than 8 during the day.
>
> Can anyone suggest an alternate way to accomplish this?
>
>

--
Met vriendelijke groeten,

Remco Post
r.post AT plcs DOT nl
+31 6 248 21 622



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