We are running a 4.2.3.2 TSM server under OS/390. We have four 3590 tape
drives that were and are working well with 3590 J tapes (the ones with
20 GB capacity without compression). We are in the process of migrating
our onsite storage pools to 3590 K tapes (the ones with 40 GB capacity
without compression). So far we have had seven of the new tapes forced
read-only because of I/O errors. We have one full 3590 K tape, and
seventeen in 'FILLING' status that have not so far had any I/O errors.
The errors have been spread across at least three of the tape drives.
In most cases, there is an OS/390 message like the following:

IOS071I 0C62,1D,ADSM, MISSING CHANNEL AND DEVICE END

and a TSM message like the following:

ANR5351E Error reading BlockID on device 0C62.

Do 3590 K tapes typically suffer the kind of infant mortality rate
we are seeing?