Still working on narrowing this down ...
The Celerra was also backing up to a Data Domain VTL, so to eliminate that as a possible root cause I unzoned the Celerra from the DD and rescanned for devices. Once the Celerra was only able to see the HP StoreOnce VTL drives, I found that I could scan on some, but not all drives. No apparent pattern yet with which drives are working and which not. I've tried starting off simply - eight drives (the minimum allowed) and one tape, then moved up to two, etc. Some drives scan and format tapes ok, some don't .
It's not an index issue, the indexing is correct from 1 to 8. Not zoning, I can still see the drives, and from the StoreOnce gui can see tapes being moved in and out. Have tried setting / not setting a device lock name on the drive config, made no difference. Have tried setting / not setting SCSI reserve options, again no difference. Have tried various block sizes when configuring the device, from 256k downward (chose that value as highest since other server backups are using the same and all will write eventually to a common physical tape library). Again, no difference with block size.
Of the 8 drives, for those that do scan/format ok I can scan and format any given tape, for those drives that don't scan/format, I cannot scan or format any tape. That seems to rule out the problem being the drive or tape configuration - all are configured the same w.r.t. size, type.
Not sure how to capture debug info for something like this. Enabling debug on the HPDP gui doesn't seem to generate anything related to the tape scanning or formatting.
