[rescue] rescuing an ailing U10...

[Scott Quinn]

Mike Meridith wrote:
> Well don't quote me on this (i.e. I could well be wrong) but I think
> Sun's firmware does a very similar thing to PC firmware ... just loads
> the first few sectors off a disk. This secondary loader (ufsboot) does
> the interpretation of the disk label and the loading of the kernel.

Pretty much, the big catch with Suns is that the disk id stuff is "in" 
partition 'a' and so if you use clueless software it can clobber them 
(at least with the Solaris/SunOS partitioning). Installation docs from 
the SunOS 4 and earlier era warn about mistakenly copying the miniroot 
to partion 'a' instead of 'b' since you'll clobber your disklabel and 
need to reboot munix and rerun format.


Michael-John Turner writes:

> Was it a SCSI or IDE disk? I'd be surprised if you had problems with an
> IDE disk, but SCSI is another story. I've had various non-Sun-firmware 
> SCSI
> disks (in particular, certain IBM firmware Seagates) that wouldn't 
> even be
> identified by the PROM without giving errors. I've heard that if one 
> finds
> the correct Sun firmware (eg in a Solaris patch), the drives can be 
> updated
> and will then work. Haven't tried it myself though.
>

I've had very few SCSI disks that have problems - at this point I can 
only think of a IBM 0664 that didn't like several computers and one 
Seagate that really didn't like an Apollo 425, but that might have been 
size-related (the machine chewed it up and spit it out when it tried to 
format, which I didn't realize DomainOS does by default). I've heard 
that you need to watch out for disk array disks (especially EMC I 
think), one type uses a nonstandard block size.

In short, my advice is try a second disk. I've never had to go through 
more than two disks to find one that will work in a machine. If you're 
labeling a disk for older versions of SunOS (offtopic, I know) it's 
much easier to label in Solaris and then move to SunOS because SunOS 
isn't very good at autoprobing disks and the native types are almost 
exclusively Sun-sold ones.