Subject: Re: Hmm. Stability problems.
To: Scott Reynolds <scottr@edsi.org>
From: Allen Briggs <briggs@puma.bevd.blacksburg.va.us>
List: port-mac68k
Date: 11/12/1995 20:32:28
> 	panic: ffs_read 0  <-and->  extended heavy load (load avg > 4.0)
> This one hasn't gone away, or at least it has shown up in several 
> different but apparently related forms.  There is always some period of 
> intense disk activity before it happens.

Hmmm...  I wonder if it's related to the crash that I very occasionally
see.  I assumed that I was getting it because of flaky hardware.  When
one of my partitions gets nearly full, I get one or two "Bad block XX"
messages where XX is some impossible number.  Then a panic: freeing free
frag.  This always leads to data loss (usually something that I can
recover...)  It also invariably happens during my nightly 'security'
runs when I'm doing some compile or something at the same time.

> One common factor that seems to be coming up is blocks from apparently 
> random places get thrown into another part of the filesystem.

Someone else saw this on a slow (MO) drive.  I have not seen it on my
system at all.

> Possible problems:  bad cable?  bad termination?  the driver doesn't like 
> having these 3 devices attached to the SCSI bus?  the driver has some 
> weird bug that is only tickled by my strange SCSI disk (was originally a 
> part of an IBM RAID subsystem)?

The driver probably has a wierd bug or two.  It's also possible that you
have bad termination or that one of the devices has a bug (unlikely).
How is your cable length?

-allen

-- 
Allen Briggs - end killing - allen.briggs@bev.net ** MacBSD == NetBSD/mac68k **
   Where does all my time go?  <a href="http://www.netbsd.org/">Guess.</a>