SSC issues: Clarifications needed for Medium Partition Page (11h)
Jan F. Rebalski
Janek_Rebalski at asd.sel.sony.com
Fri Feb 6 14:24:42 PST 1998
* From the T10 (formerly SCSI) Reflector (t10 at symbios.com), posted by:
* "Jan F. Rebalski"<Janek_Rebalski at asd.sel.sony.com>
It appears to me that the section 188.8.131.52 of X3T10/997D rev.11 omits
adequate clarification of the following scenarios:
What happens (or should happen) when none of the FDP, SDP, IDP bits are
What happens when the POFM bit is set when the CLEAR and/or ADDP bits
are set? POFM is explained only in relation to FDP, SDP, and IDP bits.
Why is the combination of (POFM = 0 and [FDP | SDP | IDP] = 1) legal at
the BOP only? How does this relate to any possible combination of the
CLEAR and ADDP bits?
The scenario of (CLEAR = 1 and ADDP = 0) is defined specifically for the
situation when one of the FDP, SDP, and IDP bits is set. None of the
other possible combinations of CLEAR and ADDP bits mention the relevance
of the FDP, SDP, and IDP bits.
All in all, the relationship among FDP, SDP, IDP, POFM, CLEAR, and ADDP
bits appears to be rather tenuous, if not somewhat incomplete. There are
additional functionalities hinted at in reference to these bits when their
interplay with partition size descriptors and the FORMAT MEDIUM command is
taken into account. If this section remains the way it is, I think that it
will cause much confusion in the potential implementations of
multi-partitioning in tape devices. At this point, I don't think it is
possible to implement a robust validation logic for Page 11h, and
consequently we may see a multitude of compatibility problems.
A relationship table listing these bits is probably called for.
Jan F. Rebalski
Advanced Storage Development, CCPG
Sony Electronics, Inc.
3300 Zanker Road, M/S SJ3B2
San Jose, CA 95134-1940
mailto:Janek_Rebalski at asd.sel.sony.com
* For T10 Reflector information, send a message with
* 'info t10' (no quotes) in the message body to majordomo at symbios.com
More information about the T10