1. GridKa May 2004 Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft Installing dCache into an existing Storage environment at GridKa Forschungszentrum Karlsruhe GmbH Institute for Scientific Computing P.O. Box 3640 D-76021 Karlsruhe, Germany Dr. Doris Ressmann Doris.Ressmann@iwr.fzk.de http://www.gridka.de

2. GridKa May 2004 Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft Forschungszentrum Karlsruhe Grid Computing Centre Karlsruhe GridKa

3. GridKa May 2004 Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft GridKa planned hardware resources 4000 3000 2000 1000 0 kSI95 CPU Disk Tape 780 CPUs 160 TB disk 300 TB tape

4. GridKa May 2004 Forschungszentrum Karlsruhe in 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Manager (TSM) TSM library management TSM is not developed for archive Interruption of TSM archive No control what has been archived dCache (DESY, FNAL) creates a separate session for every file Transparent access Allows transparent maintenance at TSM

5. GridKa May 2004 Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft dCache main components TSM with tapes pools compute nodes mountpoint gridftp srmcp file transfer head node

6. GridKa May 2004 Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft PNFS Perfectly Normal File System real data database for filenames metadata 0000000000000000000014F0 000000000000000000001510 0000000000000000000015A0 0000000000000000000017E8 000000000000000000001858 pool and tape pnfs

7. GridKa May 2004 Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft dCache interface dCache Access Protocol (dcap) compute node: dccp 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 if not in pool the data will be taken from tsm

8. GridKa May 2004 Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft Tivoli Storage Manager (tsm)

9. GridKa May 2004 Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft dCache pool node

10. GridKa May 2004 Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft Tivoli Storage Manager (tsm) after dCache tuning

11. GridKa May 2004 Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft Test Environment Problematic Hardware RAID controller 3WARE with 1.6 TB – Always Degraded mode – Rebuilding 70 kB/s or 10 MB/s – Lost data

12. GridKa May 2004 Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft TSM properties TSM disk cache overflow Allocation of tape drives (max 2) Adapt server properties for specific dCache requirements Management Class (retention time) Copy groups

13. GridKa May 2004 Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft Conclusion and Future Work More reliable hardware especially for write pools Several TSM server SRM and LCG connection Pools on parallel File system GPFS

14. GridKa May 2004 Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft