Does this indicate a hardware error?

ANR8302E I/O error on drive MT1.0.0.2 (mt1.0.0.2)
                       (OP=READ, Error Number=1117, CC=305, KEY=00, ASC=00,
                       ASCQ=00,
SENSE=70.00.00.00.00.00.00.0E.00.00.00.00.00.00-
                       .00.00.00.00.00.00.00.00., Description=Drive
failure).
                       Refer to Appendix D in the 'Messages' manual for
                       recommended action.
ANR8792E Unrecoverable drive failures on drive MT1.0.0.2
                       (mt1.0.0.2); drive is now taken offline.

This has happend twice, when I set the drive online again it works.
Is it really a hardware error, or could it be something else that makes TSM
to set this drive offline?


Regards

Sylvia Nergård