Date: Tue, 30 Mar 2004 10:30:53 +0200 From: Roberto Nunnari <roberto.nunnari@supsi.ch> To: freebsd-current@freebsd.org Subject: help! I broke the partition table of the drive with the bootable partition! Message-ID: <4069303D.9070901@supsi.ch>
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Hi all.
I was installing a new drive on my 5.2.1-p3 and I believe
I made some mistake while using fdisk and bsdlabel.. in
fact the partition table for my bootable disk has changed.
this was my fdisk amrd0 before:
web.dti.supsi.ch# cat fdisk.amrd0
******* Working on device /dev/amrd0 *******
parameters extracted from in-core disklabel are:
cylinders=4420 heads=255 sectors/track=63 (16065 blks/cyl)
Figures below won't work with BIOS for partitions not in cyl 1
parameters to be used for BIOS calculations are:
cylinders=4420 heads=255 sectors/track=63 (16065 blks/cyl)
Media sector size is 512
Warning: BIOS sector numbering starts with sector 1
Information from DOS bootblock is:
The data for partition 1 is:
sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
start 63, size 71007237 (34671 Meg), flag 80 (active)
beg: cyl 0/ head 1/ sector 1;
end: cyl 1023/ head 254/ sector 63
The data for partition 2 is:
<UNUSED>
The data for partition 3 is:
<UNUSED>
The data for partition 4 is:
<UNUSED>
and this is how it looks now..
web.dti.supsi.ch# fdisk amrd0
******* Working on device /dev/amrd0 *******
parameters extracted from in-core disklabel are:
cylinders=4420 heads=255 sectors/track=63 (16065 blks/cyl)
Figures below won't work with BIOS for partitions not in cyl 1
parameters to be used for BIOS calculations are:
cylinders=4420 heads=255 sectors/track=63 (16065 blks/cyl)
Media sector size is 512
Warning: BIOS sector numbering starts with sector 1
Information from DOS bootblock is:
The data for partition 1 is:
sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
start 0, size 70766325 (34553 Meg), flag 0
beg: cyl 0/ head 0/ sector 1;
end: cyl 308/ head 254/ sector 63
The data for partition 2 is:
<UNUSED>
The data for partition 3 is:
<UNUSED>
The data for partition 4 is:
<UNUSED>
as you can see, it is no longer bootable, and it doesn't
start at sect 63 like before but at 0
How can I fix it? I was about to give the following command
but thought I'd better ask first here...
web.dti.supsi.ch# fdisk -B
I expect the above to reinstall the boot code and to correct
the partition table.. I expect I'll be able to give that
command while the system and running and so the filesystem
mounted.
or if that doesn't work..
web.dti.supsi.ch# fdisk -B -f fdisk.conf.amrd0
also.. with the -t option the results are almost identical
to the original state, but end cyl is different.. See..
is that important?
web.dti.supsi.ch# fdisk -t -B -f fdisk.conf.amrd0
******* Working on device /dev/amrd0 *******
fdisk: WARNING line 2: number of cylinders (4420) may be out-of-range
(must be within 1-1024 for normal BIOS operation, unless the entire
disk
is dedicated to FreeBSD)
parameters extracted from in-core disklabel are:
cylinders=4420 heads=255 sectors/track=63 (16065 blks/cyl)
Figures below won't work with BIOS for partitions not in cyl 1
parameters to be used for BIOS calculations are:
cylinders=4420 heads=255 sectors/track=63 (16065 blks/cyl)
Information from DOS bootblock is:
1: sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
start 63, size 71007237 (34671 Meg), flag 80 (active)
beg: cyl 0/ head 1/ sector 1;
end: cyl 323/ head 254/ sector 63
2: <UNUSED>
3: <UNUSED>
4: <UNUSED>
and here is the fdisk.conf.amrd0 file
web.dti.supsi.ch# cat fdisk.conf.amrd0
# values extacted from old fdisk.amrd0
g c4420 h255 s63
p 1 165 63 71007237
p 2 0 0 0
p 3 0 0 0
p 4 0 0 0
a 1
Thank you for your help.
--
Roberto Nunnari -software engineer-
mailto:roberto.nunnari@supsi.ch
Scuola Universitaria Professionale della Svizzera Italiana
Dipartimento Tecnologie Innovative
http://www.dti.supsi.ch
SUPSI-DTI
Via Cantonale tel: +41-91-6108561
6928 Manno """ fax: +41-91-6108570
Switzerland (o o)
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