[gpfsug-discuss] Vmtouch on GPFS is supported?

[Alec]

You should keep in mind that GPFS primarily ships out configured for large
sequential read/write as it's you know a multimedia file system...

Not knowing your application, but assuming it maybe has a ton of little
library files and such it's trying to keep track of I'd make sure to do the
following optimizations:

 - Increase page pool maybe to 8gb or more.
 - Change maxfiles pagepool tracks from 4k to like 10k or 40k.
 - If you're not doing a separate meta device, i would ensure you are doing
that.  Then I'd also ensure it was on SSD or similar media and pinned to
SSD if over SAN.

For data like this on our AIX environment we will keep a jfs2 volume for
it.. because it will just stay in RAM because we have 100gb free.  And so
for large sorts and quick load of random I/O this outperforms GPFS.

GPFS secret benefit is that it prevents memory cache thrashing by not
caching large data.... But this may be holding your app back.  I couldn't
find/remember the setting but I believe there is somewhere where it decides
anything over like 1mb isn't worth caching, maybe that needs to be tuned
for your instance.

Alec



On Tue, Aug 15, 2023, 12:29 AM Jonathan Buzzard <
jonathan.buzzard at strath.ac.uk> wrote:

> On 15/08/2023 07:32, Uwe Falke wrote:
> >
> > second point:
> >
> > while there is probably no vmtouch4gpfs, you might check and tune your
> > gpfs parameters (pagepool size, maxFilesToCache).  But first you should
> > identify where the bottleneck is. Is your GPFS cluster spanning the VPN?
> > Suppose not. So how do you know that it is really GPFS which is delaying
> > your loading?
> >
> > nomachine is an remote desktop app, how do you load software efficiently
> > through nomachine?
>
> I would say if it takes longer launching through nomachine than
> launching locally, then the problem is nomachine. This should IMHO be
> the first thing you test.
>
> If it takes a long time launching locally the application is a steaming
> pile and you need to resolve that first.
>
> We use thinlinc which is a similar Linux remote desktop solution
> extensively to provide a Linux desktop to our users with through
> VirtualGL 3D visualization capabilities and we do not have an issue with
> excessive launch times.
>
>
> JAB.
>
> --
> Jonathan A. Buzzard                         Tel: +44141-5483420
> HPC System Administrator, ARCHIE-WeSt.
> University of Strathclyde, John Anderson Building, Glasgow. G4 0NG
>
>
> _______________________________________________
> gpfsug-discuss mailing list
> gpfsug-discuss at gpfsug.org
> http://gpfsug.org/mailman/listinfo/gpfsug-discuss_gpfsug.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://gpfsug.org/pipermail/gpfsug-discuss_gpfsug.org/attachments/20230816/4a9c5d28/attachment-0001.htm>