Proposal to add a new modifier to SCSI Write commands. -Reply

PAT LaVarre LAVARRE at iomega.com
Mon Dec 2 14:10:17 PST 1996


* From the SCSI Reflector (scsi at symbios.com), posted by:
* PAT LaVarre <LAVARRE at IOMEGA.COM>
*
> The host should only Reassign when it knows what
> to put in the new block (that is, after a failed
> Write or a Recovered Read).

As another "should" not (yet) captured in the
standard, this rule holds true for the drive, too,
yes?  (Except in response to an explicit 07h
REASSIGN command?)

> Maybe your system works differently?

Hmmm.

Seems like a system that reassigned any LBA that
ever had trouble would be more reliable - up until
the point when it ran out of reallocation space. 
(WIBNI we had a standard way to predict exhaustion
of reallocation space.)

I can't say for sure I know of a system that
reallocates unrecovered reads myself ...

... but I'm thinking I've seen host people
implement reallocation on a retry count.

Try writes ten times, try reads twenty, reassign
otherwise, loop?

Pat LaVarre

*
* For SCSI Reflector information, send a message with
* 'info scsi' (no quotes) in the message body to majordomo at symbios.com




More information about the T10 mailing list