GridKa May 2004
Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft
Installing dCache into an existing Storage environment at GridKa
Forschungszentrum Karlsruhe GmbHInstitute for Scientific Computing
P.O. Box 3640D-76021 Karlsruhe, Germany
Dr. Doris [email protected]
http://www.gridka.de
GridKa May 2004
Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft
Forschungszentrum Karlsruhe
•Grid Computing Centre Karlsruhe
•GridKa
GridKa May 2004
Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft
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Tb
yte
GridKa planned hardware resources
4000
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2000
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0
kSI9
5
CPUDisk
Tape
780 CPUs160 TB disk300 TB tape
GridKa May 2004
Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft
Tivoli Storage Manager (TSM)
• TSM library management• TSM is not developed for archive
Interruption of TSM archive No control what has been archived
• dCache (DESY, FNAL)creates a separate session for every fileTransparent accessAllows transparent maintenance at TSM
GridKa May 2004
Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft
dCache main components
TSMwithtapes
pools
compute nodes
mountpointgridftp
gridftp
srmcp
file tra
nsfer
file transfer
file transfer head node
GridKa May 2004
Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft
PNFSPerfectly Normal File System
real datadatabase for filenames
metadata0000000000000000000014F00000000000000000000015100000000000000000000015A00000000000000000000017E8000000000000000000001858
pool and tapepnfs
GridKa May 2004
Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft
dCache interface
• dCache Access Protocol (dcap) ● compute node: dccp <source file> <pnfs mountpoint>
● connection to head node● return available pool node
● copy direct into available pool node● dc_open(...);● dc_read(...);
● pool: data is precious (can't be deleted)● flush into tsm● data is cached (can be deleted from pool)
● compute node: dccp <pnfs mountpoint> <destination file>● if not in pool the data will be taken from tsm
GridKa May 2004
Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft
Tivoli Storage Manager (tsm)
GridKa May 2004
Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft
dCache pool node
20 GB
1 h
800 GB
GridKa May 2004
Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft
Tivoli Storage Manager (tsm)after dCache tuning
GridKa May 2004
Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft
Test EnvironmentProblematic Hardware
• RAID controller 3WARE with 1.6 TB– Always Degraded mode– Rebuilding
70 kB/s or 10 MB/s
– Lost data
GridKa May 2004
Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft
TSM properties
• TSM disk cache overflowAllocation of tape drives (max 2)Adapt server properties for specific
dCache requirements Management Class (retention time)Copy groups
GridKa May 2004
Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft
Conclusion and Future Work
• More reliable hardwareespecially for write pools
• Several TSM server• SRM and LCG connection • Pools on parallel File system
GPFS
GridKa May 2004
Forschungszentrum Karlsruhein der Helmholtz-Gemeinschaft