[comp.unix.microport] help needed with SV/AT 2.4.0

imdave@cbnewsc.ATT.COM (david.e.bodenstab) (04/03/89)

Hello fellow uport users!

I tried installing SV/AT 2.4.0 over 2.3.0 and have run into some
incompatability.  2.4.0 will not access any file systems on
drive 1.  It says something about a "bad partition end record"
sometimes.  If I boot the 2.3.0 kernel, then there's no problem.

I've got a ST4096 for drive 1, with a 46M unix partition, and
a 30M dos partition.  The unix partition is/was split into 3
smaller file systems using divvy.

So, I tried `divvy -u 1' to "rebuild the slice table" as
suggested in the release notes.  Disaster!  Now, 2.4.0
still did not access drive 1, and 2.3.0 was only able
to read /dev/dsk/1s0.

I tracked this down -- the partition end record is the last
sector of the unix partition on each drive.  When I did a
`divvy -u 1', the start sector and number of blocks had been
zeroed -- now I know what "rebuild the slice table" means. :^)
Since I knew where my partitions had been, and their sizes,
I was able to patch the partition end record for drive 1
back to what it had been.  However it looks like to get
2.4.0 to access my drive 1, I'll have to back it up (all
40M) to diskette, and do a `divvy 1' to remake all the
file systems.

My guess is that 2.3.0 is interpretting the partition end
record differently than 2.4.0.  The driver reads the 2.3.0
partition end record, sees that there are no valid unix
partitions and/or slices 1s0 through 1s3, and then refuses
to read the disk.  A `labelit /dev/dsk/1s[0-3]' always responds
with "cannot read superblock".  So, if I knew what a 2.4.0
partition end record looked like, maybe I could just fix
my partition end record and avoid having to backup/restore.

What I would like is for someone who has installed 2.4.0
on a two-drive system, and having the unix partition on drive 1
containing at least two of 1s[0-3], to dump their partition end records
and mail the results to me.  Do something like the following for
drive 0 and drive 1:

	/etc/divvy -d drive >divvy.out
	/etc/ddump drive cyl head sector >ddump.out
	/etc/fdisk | tee fdisk.out
	   (list the partition table)
	df -t >df.out

Note that cyl,head,sector is the last sector in the unix
partition of each drive.  Maybe with this info, I can figure
out what my partition end record needs to contain.

Thanks in advance!

Dave Bodenstab
...att!iwsl8!imdave