Lustre discuss - Jul 2010 - Per directory quota

I know Lustre can do quotas per user, but can Lustre do quotas on a per
directory basis? I can''t work out how to do this from the manual.

To be more specific, the software we use[1] is written by people using
GPFS and we''d like an equivalent to the GPFS command:

	mmlsquota -j

which AIUI finds out how much space is used under a directory.

We could use

	du --summarize mydirectory

but for a directory containing a large number of files, this takes a 
long time - and is presumably not very  efficient. If there were an "lfs 
du" it would presumably be more efficient, but even so, probably still 
resource intensive.

Am I missing something?

[1] http://storm.forge.cnaf.infn.it/home


Chris

On Jul 16, 2010, at 7:17 AM, "Christopher J.Walker" <C.J.Walker at
qmul.ac.uk
 > wrote:
> I know Lustre can do quotas per user, but can Lustre do quotas on a  
> per
> directory basis?
No, Lustre does not support directory (fileset) based quotas.

> I can''t work out how to do this from the manual.
>
> To be more specific, the software we use[1] is written by people using
> GPFS and we''d like an equivalent to the GPFS command:
>
>    mmlsquota -j
>
> which AIUI finds out how much space is used under a directory.
>
> We could use
>
>    du --summarize mydirectory
>
> but for a directory containing a large number of files, this takes a
> long time - and is presumably not very  efficient. If there were an  
> "lfs
> du" it would presumably be more efficient, but even so, probably still
> resource intensive.
Without size-on-mds, either way would have to query both the mds and  
each OST to get the size info.  Not being that familiar with size-on- 
mds, it does seem likely that "du" would still have to query the OST  
for size info, even when "ls -l" does not.

> Am I missing something?
>
> [1] http://storm.forge.cnaf.infn.it/home
>
>
> Chris
>
> _______________________________________________
> Lustre-discuss mailing list
> Lustre-discuss at lists.lustre.org
> http://lists.lustre.org/mailman/listinfo/lustre-discuss

>Without size-on-mds, either way would have to query both the mds and  
>each OST to get the size info.  Not being that familiar with size-on- 
>mds, it does seem likely that "du" would still have to query the
OST
>for size info, even when "ls -l" does not.
As someone who has spent the past week or two struggling with the
size-on-mds code ... IF everything is working right (a reasonably-sized
IF), then it should not.  AFAIK, "du" is simply calling stat(), which
is the same thing "ls -l" is doing.  Certainly part of the information
you store as part of SOM is the disk block usage, which is what du is
adding up.

--Ken