Hi Roger,
        Maybe I am wrong. But I have'nt seen such a behaviour as described
by you. I have seen many times over all the devices in use out of out the
four tape drives that we've got. may be you should check the mountlimit
option.


Besides I was right in my analysis of optical media being the slowest of the
three i.e. out of Hard disks  , TAPES and Optical media.

Some of the tapes are faster than the Hard disks themselves.

After some analysis I also confirmed that optical media is most reliable of
the lot. However for mainframe environment it may not really reach  your
expected level of performance. But again I should say that restoration of r
small individual files , optical media does the job fairly good.