[gpfsug-discuss] GPFS+TSM+HSM: staging vs. migration priority

Dominic Mueller-Wicke01 dominic.mueller at de.ibm.com
Wed Mar 9 09:35:56 GMT 2016


Hi Jamie,

I see. So, the recall-shutdown would be something for a short time period.
right? Just for the time it takes to migrate files out and free space. If
HSM would allow the recall-shutdown the impact for the users would be that
each access to migrated files would lead to an access denied error. Would
that be acceptable for the users?

Greetings, Dominic.

______________________________________________________________________________________________________________

Dominic Mueller-Wicke | IBM Spectrum Protect Development | Technical Lead |
+49 7034 64 32794 | dominic.mueller at de.ibm.com

Vorsitzende des Aufsichtsrats: Martina Koederitz; Geschäftsführung: Dirk
Wittkopp
Sitz der Gesellschaft: Böblingen; Registergericht: Amtsgericht Stuttgart,
HRB 243294



From:	Jaime Pinto <pinto at scinet.utoronto.ca>
To:	Dominic Mueller-Wicke01/Germany/IBM at IBMDE
Cc:	gpfsug-discuss at spectrumscale.org
Date:	08.03.2016 21:38
Subject:	Re: [gpfsug-discuss] GPFS+TSM+HSM: staging vs. migration
            priority



Thanks for the suggestions Dominic

I remember playing around with premigrated files at the time, and that
was not satisfactory.

What we are looking for is a configuration based parameter what will
basically break out of the "transparency for the user" mode, and not
perform any further recalling, period, if|when the file system
occupancy is above a certain threshold (98%). We would not mind if
instead gpfs would issue a preemptive "disk full" error message to any
user/app/job relying on those files to be recalled, so migration on
demand will have a chance to be performance. What we prefer is to swap
precedence, ie, any migration requests would be executed ahead of any
recalls, at least until a certain amount of free space on the file
system has been cleared.

It's really important that this type of feature is present, for us to
reconsider the TSM version of HSM as a solution. It's not clear from
the manual that this can be accomplish in some fashion.

Thanks
Jaime

Quoting Dominic Mueller-Wicke01 <dominic.mueller at de.ibm.com>:

>
>
> Hi,
>
> in all cases a recall request will be handled transparent for the user at
> the time a migrated files is accessed. This can't be prevented and has
two
> down sides: a) the space used in the file system increases and b) random
> access to storage media in the Spectrum Protect server happens. With
newer
> versions of Spectrum Protect for Space Management a so called tape
> optimized recall method is available that can reduce the impact to the
> system (especially Spectrum Protect server).
> If the problem was that the file system went out of space at the time the
> recalls came in I would recommend to reduce the threshold settings for
the
> file system and increase the number of premigrated files. This will allow
> to free space very quickly if needed. If you didn't use the policy based
> threshold migration so far I recommend to use it. This method is
> significant faster compared to the classical HSM based threshold
migration
> approach.
>
> Greetings, Dominic.
>
>
______________________________________________________________________________________________________________

>
> Dominic Mueller-Wicke | IBM Spectrum Protect Development | Technical Lead
|
> +49 7034 64 32794 | dominic.mueller at de.ibm.com
>
> Vorsitzende des Aufsichtsrats: Martina Koederitz; Geschäftsführung: Dirk
> Wittkopp
> Sitz der Gesellschaft: Böblingen; Registergericht: Amtsgericht Stuttgart,
> HRB 243294
> ----- Forwarded by Dominic Mueller-Wicke01/Germany/IBM on 08.03.2016
18:21
> -----
>
> From:		 Jaime Pinto <pinto at scinet.utoronto.ca>
> To:		 gpfsug main discussion list <gpfsug-discuss at spectrumscale.org>
> Date:		 08.03.2016 17:36
> Subject:		 [gpfsug-discuss] GPFS+TSM+HSM: staging vs. migration
priority
> Sent by:		 gpfsug-discuss-bounces at spectrumscale.org
>
>
>
> I'm wondering whether the new version of the "Spectrum Suite" will
> allow us set the priority of the HSM migration to be higher than
> staging.
>
>
> I ask this because back in 2011 when we were still using Tivoli HSM
> with GPFS, during mixed requests for migration and staging operations,
> we had a very annoying behavior in which the staging would always take
> precedence over migration. The end-result was that the GPFS would fill
> up to 100% and induce a deadlock on the cluster, unless we identified
> all the user driven stage requests in time, and killed them all. We
> contacted IBM support a few times asking for a way fix this, and were
> told it was built into TSM. Back then we gave up IBM's HSM primarily
> for this reason, although performance was also a consideration (more
> to this on another post).
>
> We are now reconsidering HSM for a new deployment, however only if
> this issue has been resolved (among a few others).
>
> What has been some of the experience out there?
>
> Thanks
> Jaime
>
>
>
>
> ---
> Jaime Pinto
> SciNet HPC Consortium  - Compute/Calcul Canada
> www.scinet.utoronto.ca - www.computecanada.org
> University of Toronto
> 256 McCaul Street, Room 235
> Toronto, ON, M5T1W5
> P: 416-978-2755
> C: 416-505-1477
>
> ----------------------------------------------------------------
> This message was sent using IMP at SciNet Consortium, University of
> Toronto.
>
>
> _______________________________________________
> gpfsug-discuss mailing list
> gpfsug-discuss at spectrumscale.org
> http://gpfsug.org/mailman/listinfo/gpfsug-discuss
>
>
>
>






          ************************************
           TELL US ABOUT YOUR SUCCESS STORIES
          http://www.scinethpc.ca/testimonials
          ************************************
---
Jaime Pinto
SciNet HPC Consortium  - Compute/Calcul Canada
www.scinet.utoronto.ca - www.computecanada.org
University of Toronto
256 McCaul Street, Room 235
Toronto, ON, M5T1W5
P: 416-978-2755
C: 416-505-1477

----------------------------------------------------------------
This message was sent using IMP at SciNet Consortium, University of
Toronto.



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://gpfsug.org/pipermail/gpfsug-discuss_gpfsug.org/attachments/20160309/1ef7bd45/attachment-0002.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: graycol.gif
Type: image/gif
Size: 105 bytes
Desc: not available
URL: <http://gpfsug.org/pipermail/gpfsug-discuss_gpfsug.org/attachments/20160309/1ef7bd45/attachment-0002.gif>


More information about the gpfsug-discuss mailing list