SUMMARY: disk error - no defect list found

From: K. Bader (
Date: Tue Mar 21 1995 - 04:30:57 CST

Sun Managers,
        Sorry for the late summary. I've been pretty busy
working on this problem. Torsten Metzner hit it nail on head.
The error I was getting was Block # (cyl/0/0), Fatal non-media error
(illegal request). Unfortunately, I had already gotton past this
problem probably accidentally by changing the Format.dat entry
        disk_type = "Seagate ST12550N"\
        : ctlr = MD21 : fmt_time = 4 \
        : rpm = 7200 : bpt = 40000 \
        : nsect = 81 : ncyl = 2714 : pcyl = 2708 : nhead = 19 \
        : acyl = 1: atrks = 19 : trks_zone = 19 : asect = 9
        which I got from scsiping program
        disk_type = "Seagate ST12550N"\
        : ctlr = MD21 : fmt_time = 4 \
        : cache = 0x0 : trks_zone = 19 : asect = 9 : atrks = 19 \
        : ncyl = 2747 : acyl = 2 : pcyl = 2708 : nhead = 19 \
        : nsect = 80 : rpm = 7200 : bpt = 40960

        which I got from anonymous ftp at in

For some reason the error went away after I changed this.
I then got the original defect list, committed, reformated, and
ran analyze/compare as suggested by Peter Allen. Now I have
the disks formatted with defect lists and am trying to determine
whether or not my data which was on them before they had
a defect list is corrupt.
According to Torsten, the format error occured because the disk tries
to write a backup label on cylinder number <data_cylinders>+1.
His solution which I did not try since this problem was resolved is :

> (1) Format the disk.
> (2) Select the disk again. Now give a new value for
> <data_cylinders>, which is
> <old_data_cylinders>-2.
                Do this by selecting "other" for disk type
                and typing in the values.
> (3) Now you can partition and label the disk.

Torsten also told me it's not a good ideas to try to get the
data off these disks; however, I really don't have much choice.
I can't go back a month to before the disks were in operation
so I am in the process of restoring a backup from this time and
am going to try to compare the data.

QUESTION: If anyone has any idea how to verify the integrity
           of data that was running on a disk with no defect list,
           I would like to hear it.

Sorry Torsten, you gave me great advice but I'm being stubborn.

Another response worth noting which I received after I had already
reformatted all the drives was from Steinar Haug:

> It is perfectly possible to get the manufacturer's defect
> list without having to reformat the drive - even if Sun
> wants you to believe otherwise.
> Here is a recent posting I made about this.

> 1. How to get a usable defect list without having
                 to format the disk.
> The following trick is courtesy of Parity. Assume you
                   have a disk with format saying 'no defect list found':
> - Go to the defect submenu, do 'original' to extract
                manufacturer's defect list. 'commit' the changes.
                Quit the defect menu (ignore the warning about
                needing to format the disk).
> - Label the disk.

> - And here's the trick: After you have labeled it,
                  do 'backup' to look for a backup label. Answer yes
                  you *do* want the backup label even if the disk
                  has a primary label.

> Presto, you now have a disk with a usable defect list.

Thanks to all that responded:


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