SUMMARY: Inconsistent disk label. Problem?

From: Peter Chapin <pchapin_at_twilight.vtc.vsc.edu>
Date: Thu, 10 Sep 1998 14:57:24 -0400 (EDT)

Sorry about the delay in getting this summary out the door. I had an
(unexpectedly) long weekend. It's a long story and you don't want to
know.

Thanks to

        "Dr. Tom Blinn, 603-884-0646" <tpb_at_doctor.zk3.dec.com>
        alan_at_nabeth.cxo.dec.com
        Jim Belonis <belonis_at_dirac.phys.washington.edu>
        Toni Harbaugh-Blackford <harbaugh_at_ncifcrf.gov>

for their responses.

The answer to my question was, basically, "don't worry about it." With
modern disks the basic disk geometry is obtained from the drive hardware
and not from the label. Here is a specific quotes from one of my
responses.

Dr. Tom Blinn:

"It's just a warning (like it says). You can use the scu utility to
verify the disk geometry; you'll find that what it reports in the label
for the number of sectors per cylinder isn't what the disklabel utility is
using, I suspect. (The label says 1376, but disklabel's calculations show
that the right value is probably 1584 sectors per cylinder.)"

"Also, due to the size of the disk and the way UFS file systems work,
there is wasted space in the last cylinder, to the tune of 1504 sectors
(almost a full cylinder). There are ways to get rid of this message, but
it's not at all worth the effort."

My original posting follows.

-----> original <------

Hello!

I'm preparing to move some files to another partition on the same disk.
The target partition was used for files in the past, but the files on it
are no longer relevant to anything. In preparation I used newfs to create
a new UFS file system on that partition like so

        # newfs /dev/rrz0h

This seemed to work fine but I did get the following warnings:

Warning: Calculated sectors per cylinder (1584) disagrees with disk label
         (1376).
Warning: 1504 sectors in last cylinder unallocated.

I have not touched the disk label for this disk since taking the machine
out of the box. Digital Unix came pre-installed on this unit.

Is this something I should worry about? I'd hate to get a corrupt file
system in a few months!

-----> end original <-----

*****************************************************************************
Peter
pchapin_at_twilight.vtc.vsc.edu http://twilight.vtc.vsc.edu/~pchapin/
Received on Thu Sep 10 1998 - 18:58:27 NZST

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