Re: Disk Problems

[Ib-Michael Martinsen <i.m.martinsen%gmail.com@localhost>]

Hi Robert, you wrote:

 > They look identical to me, and it looks as if you're just changing x to x
 > for all values, nothing would be expected to change would it?
 > 
 > The only difference I see if in the bios geometry values (wd0 has 63 "heads"
 > and wd1 only 18).   That's an irrelevant setting for any modern drive,
 > just ignore it (it is possible to change, but isn't worth the bother).


The disk settings are identical except for the BIOS settings
and the partition alignment and offset parameter. I am and was
unsure about the consequences of this.

 >   | I have tried to copy the first 8K from wd0 to wd1 with
 >   | 
 >   | dd if=/dev/rwd0d of=/dev/rws1d bs=512 count=16384
 > 
 > That's 8M. not 8K, not that it really matters (unless you're
 > destroying data along the way).

You are right, my mistake. But  actually I did wipe out the
first 8M of wd1 before I recreated the correct placed raid
partition.


 > If you really want to make them appear identical, use fdisk and alter the
 > bios geometry numbers of wd1 (or wd0).


I tried to do that. When I change the parameter settings for
wd1, this is what happens:

root@asus:/root # fdisk -A 3963/63 -b 1024/63/63 /dev/rwd1d
Disk: /dev/rwd1d
NetBSD disklabel disk geometry:
cylinders: 3876021, heads: 16, sectors/track: 63 (1008 sectors/cylinder)
total sectors: 3907029168

BIOS disk geometry:
cylinders: 1024, heads: 63, sectors/track: 63 (3969 sectors/cylinder)
total sectors: 3907029168

Partitions aligned to 3963 sector boundaries, offset 63

Partition table:
0: NetBSD (sysid 169)
    start 2048, size 3907027120 (1907728 MB, Cyls 0/32/33-984386/17/63), Active
1: <UNUSED>
2: <UNUSED>
3: <UNUSED>
Bootselector enabled, timeout 20 seconds.
First active partition: 0
root@asus:/root # 


root@asus:/root # fdisk /dev/rwd1d
Disk: /dev/rwd1d
NetBSD disklabel disk geometry:
cylinders: 3876021, heads: 16, sectors/track: 63 (1008 sectors/cylinder)
total sectors: 3907029168

BIOS disk geometry:
cylinders: 1024, heads: 18, sectors/track: 63 (1134 sectors/cylinder)
total sectors: 3907029168

Partitions aligned to 1134 sector boundaries, offset 63

Partition table:
0: NetBSD (sysid 169)
    start 2048, size 3907027120 (1907728 MB, Cyls 1/14/33-3445351), Active
1: <UNUSED>
2: <UNUSED>
3: <UNUSED>
Bootselector enabled, timeout 20 seconds.
First active partition: 0
root@asus:/root # 

i.e. fdisk acknowledges the changes in the settings but
reading settings again shows nothing has changed.

I find that a bit disturbing!


 >   | Does anyone know how to get the full device list back in the boot
 >   | menu?
 > 
 > This one I have no idea about.

Ah, too bad.

Maybe the list originates from an older MBR boot-loader?
At some point I had to boot from a v5.0 install CD or a
v5.1 LiveCD (I do not recall which one) and restore the
MBR which where damaged on both wd0 and dw1.

If somebody else knows an answer I would sure like to know
it too.

Thank you for your feedback.

Kind regards
  Ib-Michael
-- 
Email: i.m.martinsen(at)gmail.com
Running NetBSD/i386 v6.1.4

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