SUMMARY: scsi disk format prob/ques

From: Chuck Campbell (
Date: Fri Jan 27 1995 - 13:41:38 CST

first I want to thank everyone who responded. I learned a couple of things,
and confirmed my worst fears as well.

One suggestion was to drop to single user mode, run fsck, then dump the file
system(s). I agree, but the fsck was complaining soooo much (I stuck it out
and spent 2+ hours answering questions and trying to salvage/repair
everything it asked about, but fsck had many, many, many read and/or write

Others suggested that a bad format.dat (label) could cause this. I verified
the number of cylinders, tracks, sectors and blocks per sector.

A suggestion about termination and/or bad scsi cables was made, so I
removed all external devices, and still had the problems. An interesting
side effect is that the fastest device on the bus tends to generate the error,
not the device which is really having the problem. When I removed the
external disk I originally thought was having a problem, it became very
clear that the internal (boot device) was the disk with a problem.

I already had a (suspected good) backup from the day before with no errors,
so I opted to format the drive.

The correct process (cook book style) as I understand it is:
1)run format
  define the disk type (get correct parameters for the drive)
  analyse (be sure and do setup first though defaults work fine, but if you
    select repair bad sectors, it will damage any files, even in a
    non-destructive test)
    if you find bad blocks that analyse doesn't fix, go to repair and
    repair them
  go to defect
    commit the changes you have made
  go to format and format the drive
  go to partition and set up your filesystem(s)
  label the disk
  exit format
2)run newfs for each new filesystem
3)install the miniroot from cd
4)run suninstall

Suninstall kept falling over with read and/or write errors at lots of
different places. I kept repeating the above with manual repairs of reported
bad blocks in format.

Another suggestion was that bad power to the device could cause similar
effects. The power supply was tested, and was found to be ok.

In suninstall, you can choose to re-partition, or even reformat the drive. As
it turned out I have a bad disk (suspected controller electronics) which
intermittently would have read/write errors anywhere on the disk. Throwing
out the defects list and analysing again gave a different set of defects...

It was also suggested that I might have forgotten to do a newfs prior to
installing, but suninstall will run it for you if you haven't done it
already, and you happen to be having suninstall format and partition for you.
bought a new disk (micropolis, 2+Gb, 5 yr warranty) and all is back in
order now. Thanks again to everyone for the help with the format details
and trouble shooting tips.

Any errors here are mine in transcription, and if I have missed anyone in the
acknowledgements, I apologise.


Steve Raffensberger
Paul E. Silu
Larry Ash
Robert Tag
Kev (my apologies, I lost your last name in my editting)
Claudia Mandara
Ercole Colonnese

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