Hi Jens,
Like Graeme said, I'll still be at CERN so will not be able to make the
meeting.
The dCache session was interesting, in particular the fact that they will
release the source code with the next release and the personnel changes at
DESY.
A number of the issues that GridPP raised with dCache.org appear to have
been addressed, but there are still some that the developers may not look
at implementing, particularly quotas.
With this in mind I think that we will have to recommend to dCache sites
that they implement quotas at the pool level by assigning VOs to their own
pool group. These pool groups will have to be populated with dCache pools
with sizes that do not necessarily equal the size of the filesystem
partition where they reside. e.g. on a 1TB partition you could create 2
0.5TB dCache pools, one of which could be assigned to CMS and the other to
ATLAS. Using this setup so that VOs do not share disk pools will also
improve the storage accounting since the dCache information plugin will
then correctly report how much storage is available and used by each VO.
Implementing such a system will obviously increase the number of
active dCache pools, but this should not be a problem for our
relatively small dCache sites. The FNAL production dCache operates with
~300 pools hundreds of TBs of disk.
Owen and I plan to discuss the best way of creating such a pool setup
using YAIM. However there is a problem in trying to create the VO specific
pools for our dCache sites who do not have sufficient empty space in their
existing pools for resizing to occur. We will have to think about the
best way of dealing with this situation.
Cheers,
Greig
On Tue, 20 Jun 2006, Jensen, J (Jens) wrote:
> http://agenda.cern.ch/fullAgenda.php?ida=a063006
>
> Now uploaded.
>
> Thanks,
> --jens
>
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Dr Greig A Cowan http://www.ph.ed.ac.uk/~gcowan1
School of Physics, University of Edinburgh, James Clerk Maxwell Building
TIER-2 STORAGE SUPPORT PAGES: http://wiki.gridpp.ac.uk/wiki/Grid_Storage
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