Present:
Bristol: Tim, Simon (?)
Edinburgh: Phil
Oxford: Rhys
RAL: Andrew, Jens, Owen, Tara
Apologies: David, Peter, Steve.
0. Site update
Oxford and Edinburgh are both installing LCG2, intending
to become part of the LCG testbed-that-is-not-called-testbed.
Currently with 3 TB (Oxford) and 24 TB (Edinburgh) disk.
1. SRB
CMS had expected to phase out the use of SRB over a period
of 6 months, but this now appears to have been sped up.
Tony Wildish is copying files from SRBs at Tier 1s into
CASTOR at CERN. He should notify RAL when this is done;
Bristol will ask Tony to notify a person at RAL; Andrew
will decide who that lucky person will be.
Phil announced that Edinburgh is working on an SRM->SRB
interface. While the HEP world now seems to use SRB less,
the non-HEP world uses SRB a lot, also to the Atlas storage
facility (ADS) at RAL. The non-HEP world, however, does
not yet use SRM, but perhaps this will change with SRM now
in GGF (not as SRM, but as GSM IIRC).
It was noted that as SRB is phased out, an SRM interface to
the Atlas storage is required. See next point.
2. SRM
Reminder: SRM is a *control* *interface*; the entitiy providing
such an interface is called a Storage Element (roughly speaking).
For disk SEs, there are currently two options: d-Cache has
an SRM on top of it, written by Fermilab. Not open source though,
at the moment, but opensourcy noises have been heard from the
d-Cache camp (albeit the DESY one).
The other is the EDG SE which now also has an SRM interface but
there are issues of scalability with the current core which need
to be addressed before it goes to production. The interface
has been tested extensively with the d-Cache SRM client srmcp
and with GFAL. Tests with edg-rm will follow soon.
Neither of those have been deployed as interfaces to ADS yet.
Interfacing either one to ADS should not be difficult.
It was remarked that the LCG SRM clients, the edg-rm and the GFAL
library, can both access the ADS via the EDG SE's old (EDG) interface.
So experiments *can* use LCG middleware to write data into ADS.
However, when an SRM is deployed later, whether the dCache one or
the EDG one, the question of migrating the metadata needs to be
addressed. A plan for this exists for the EDG SE (in fact with the
current metadata upgrade to the EDG SE, no migration effort is required
when upgrading to SRM); effort required for dcache SRM must be
investigated.
It is worth remarking that while the edg-rm and the GFAL library
are both SRM clients distributed with LCG2, the edg-rm uses GridFTP
for file transfer (by default) whereas GFAL requires RFIO.
3. Local disk management
Not much done yet. Owen S mentioned that GFS has now become Open Source
and asked if anyone had experience with it yet.
4. AOB
None.
Thanks,
--jens
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