[comp.sys.next] Infamous "Bad Disk" message...

garnett@cs.utexas.edu (John William Garnett) (02/12/91)

Well, its finally (after only three months actually) happened to me.

I attempted to boot my od + 40MB swapdisk 030 cube yesterday and
received the "Bad Disk" icon.  Booting using bod from monitor
mode gives:

	od0a: read failed (uncorrectable ECC error) 4149:0:0
	od0a: read failed (uncorrectable ECC error) 4149:0:2
	blk0 boot: od() odmach
	od0a: read failed (ECC) 4149:0:0
	od0a: read failed (bitmap bad but no alternate found!) 19579:0:12
	no valid disk label found
	device couldn't set file system sector size
	load failed

I took this same disk to another system and mounted it (wasn't able
to try booting from it).  All of the files on the disk appear to
be intact.  I am assuming that some boot block was trashed.  Does
anyone recognize this particular error?  Is it safe to reuse this
disk?  (that is, assuming that BuildDisk will make it bootable
once more).

Anybody know the likely cause of the above problem?  The cube was
bought new and has only been in use for about three months.  The
environment is not very dusty (subjective judgement).  I rarely
leave it powered on for more than a couple of days at a time
(not attached via UUCP yet...).  I'd like to avoid this problem
in the future.

Thanks...
-- 
John Garnett
                              University of Texas at Austin
garnett@cs.utexas.edu         Department of Computer Science
                              Austin, Texas

garnett@cs.utexas.edu (John William Garnett) (02/12/91)

In article <1083@nada.cs.utexas.edu> garnett@cs.utexas.edu (John William Garnett) writes:
>Well, its finally (after only three months actually) happened to me.
>
>I attempted to boot my od + 40MB swapdisk 030 cube yesterday and
>received the "Bad Disk" icon.  Booting using bod from monitor
>mode gives:
>
>	od0a: read failed (uncorrectable ECC error) 4149:0:0
>	od0a: read failed (uncorrectable ECC error) 4149:0:2
[stuff deleted]

I wrote the above note...  The reason I am replying to my own post
is that this same optical disk that refused to boot at least four
times in a row is now working perfectly.  This has me at least as
worried as when it stopped working...  What is going on?  Could
this have something to do with the defective optical disk drives
(being replaced by NeXT) mentioned in a previous post?

-- 
John Garnett
                              University of Texas at Austin
garnett@cs.utexas.edu         Department of Computer Science
                              Austin, Texas