You should be able to come up with the tape device names on RHEL4 using a similar AIX OS commands as lscfg and extract the WWN and match it with TSM q drive f=d or the show command
with ensuring drive mapping on reboot. this is a combination of the OS and hardware device. Drive mapping is a funtion of the pathing in TSM.
As long as there are no changes on the h/w , communication path -cabling (drive serial numbe/wwn - e.g replacement) & tape library & OS (device drive defitions changes) machine reboot should not cause issues with TSM drive/library paths, unless of course it could not communicate with the communication path due to above changes on h/w & os. If using san switch zoning this might also be another 'problem area' to check
I think to make things easier - don't think about TSM 1st - make sure your OS definitions (wwn & serial numbers) of you drives, communication (HBA/FC) from the RHEL server to the drives are correct, in tact.
, then you can start ensuring TSM is getting the right info from the OS.
hope this helps...