Hi, Paul - You have your work cut out for you with that train-wreck of a system. I'd begin by questioning the need for all that DB content... There may be abandoned filespaces which should go, obsolete retention periods which no one has looked at in years, and perhaps even Expirations which never run to completion. As to performance, I'd begin by inspecting SCSI topology, to assure no dumb stuff, like tape and disk on the same cable. Next I'd review the LTO microcode levels, as older levels had serious problems (see "LTO performance" in ADSM QuickFacts). The "sleep" may be the drive struggling to load and position the tape. You might consider a tape case study using the tapeutil command, or the like, to get some baseline numbers on the performance of those drives and tapes for comparison as improvements are pursued.
The disk layout certainly needs a lot of review, as it doesn't seem to make sense, even if one is not familiar with EMC boxes. Only as very last resort would I even consider db unload/reload: that's ill-advised even in the best of circumstances, as proven dangerous and often unproductive. Richard Sims
