UDA50 problems

[Neil Todd @ UK.AC.MAN.CS.UX]

In article <296 at tikal.UUCP> you write:
>Configuration:
>	VAX 11/750
>	4.1bsd Unix
>	1 UDA50 disk controller, 2 RA81's
>	TU78 tape controller with 2 slaves
>
>Problem messages:
>	uda0: soft error, disk transfer error, unit 1
>	uda0: soft error, SDI error, unit 1, event 0353
>
>	uda0: soft error, disk transfer error, unit 0
>	uda0: soft error, SDI error, unit 0, event 0353
>
>    The SDI error message is always paired with the disk
>    transfer error message.
>    Notice no sector numbers.  The messages occur sometimes 3
>    hours apart, sometimes 24 hours apart, but usually not in
>    bunches.  Typically, only 2-6 occur per day on a fairly
>    active system.
>
>Other:
>	Out of 3 identical installations, we get these error
>	messages on only one.  The system doesn't crash when
>	these messages occur, but peculiar things happen (like
>	the autoboot sequence pausing (until a key is hit)
>	just before /etc/rc is run (no, we don't have rc prompt
>	for anything)).
>
>Anybody have experiences with these errors?
>We have had DEC field service on this for weeks (months?),
>and they don't seem to know what to do.  We have no manuals on
>the UDA50 (the computers are installed at customer sites),
>so if anybody out there does, maybe telling us what
>event 0353 is would be of some help(?)
>
>Thanks in advance.

The event 353 stuff is to do with "drive detected errors"
to quote the MSCP Basic disk functions Manual. I think that
it turns up because the disk has got a bad block. In spite of
what many people think neither the standard driver nor
the hardware will revector the bad block. 

The RIACS uda driver will fix this problem.

Neil Todd

JANET :- neil at uk.ac.man.cs.ux
UUCP  :- ...!mcvax!ukc!man.cs.ux!neil
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P.S. My DEC man didn't have a clue either.