Migration to T10K tapes

Some of the Fermi data hosted in xrootd are migrated to HPSS. On November 12, 2009 HPSS had been upgraded and since that date data are written to the new T10K tapes. I February/March 2010 data that were written to HPSS before the upgrade were moved from the old tapes to the new tapes.

Failure during migration

One file:

/glast/Data/Flight/Level1/LPA/prod/1.59/recon/r0237217627_v002_recon.root

could not be moved as there were repeatedly read errors. The file was still on the xrootd cluster and has been re-migrated.

Validation

After the all Fermi files were moved to T10K tapes about 10% of the files were staged back to disk and the checskum of the files (cksum) were compared to the values from the Fermi data-catalog. The file listings from the old tapes are still available and for the validation 10% (rounding up) from each listing were selected. The file listing from 681 old tapes were used.

• Files staged 6408
• Files with good checksums 6260
• Files with a checksum mismatch 2
• Files staged but mo entry in the data-catalog 146
• The total size of files staged was about 16TB

The two files that showed a mismatch of the checksums between the staged file and the data catalog are:

In both cases the files sizes agree with the values in the data catalog. The checksums of the staged files also agree with the file versions available on the xrootd disks.