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Dear Tier3 admins,
ATLAS grid sites have been migrating to SL6 over the past few
months and major issues are now resolved. We encourage all Tier3
sites to start migrating to SL6 and, at the same time, to cvmfs
2.1.
As this is a disruptive process to users, we recommend to migrate
before December 1st, 2013 so that there is a buffer before experts
are unavailable during the holiday period and also to avoid
migrating in January/February, when it might prove too disruptive
as physicists finalize their results for the Moriond conference.
Delaying is also inadvisable as there will be an ATLAS deadline
(not known yet) to stop SL5 support as well as when cvmfs 2.0 is
cut off from access.
Note that for ATLASLocalRootBase:
- some software will not be installed with latest SL5 versions;
e.g. future root versions will be released only for SL6.
- SL6 32-bit OS is unsupported in ATLASLocalRootBase. Please
migrate to 64-bit OS with SL6.
For this migration, here are documentation which may be helpful:
1. For SL6:
https://twiki.cern.ch/twiki/bin/view/AtlasComputing/RPMCompatSLC6
which
has a list of additional required rpms for ATLAS
Notice
that instead of installing each rpm listed above, you can install
the HEP_OSlibs_SL6 metapackage rpm - (but keep it updated).
https://twiki.cern.ch/twiki/bin/view/LCG/SL6DependencyRPM
If
you choose this route, please consult your cloud support first.
Note that this metarpm package is used for Tier1/2 grid sites and
will install software required for all LHC experiments and is
recommended by WLCG.
Alternately,
if you only want ATLAS required software (as on the ATLAS
RPMCompatSLC6 page), please do this after installing cvmfs on your
SL6 machine:
setupATLAS
diagnostics
checkOS
which
will list what is missing and how to install. (You should run
this after the migration to check that there are no missing rpms
even if you install the HEP_OSlibs_SL5 rpm.)
2. For cvmfs 2.1, the latest recommended version is 2.1.15:
https://twiki.cern.ch/twiki/bin/view/AtlasComputing/Cvmfs21
3. For sites using xrootd:
There
is a glibc bug that will affect xrootd storage and clients in SL6.
The work around is to
set
MALLOC_ARENA_MAX=1 (or small value)
see
this URL:
https://indico.cern.ch/getFile.py/access?contribId=12&sessionId=0&resId=0&materialId=slides&confId=261676.
(see
page 5.)
Note that after the migration, users should be able to continue
using SL5 releases as before. (e.g. for Athena releases,
setupATLAS
asetup
17.2.8.7,slc5
(ie append slc5 for slc5 releases.) There are native Athena slc6
releases available but they are not yet used for production; For
details, please refer here:
http://atlas-computing.web.cern.ch/atlas-computing/projects/releases/status/
Thanks !
regards,
Asoka (with many thanks to those in
cc for feedback, discussions)
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Adr: ATLAS Tier-1,
TRIUMF, 4004
Wesbrook Mall,
Vancouver B.C. V6T
2A3, Canada
Tel: (604) 222-7496
Fax: (604) 222-1074
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