Problems with booting & MBR
vdm.fbsd at virgilio.it
vdm.fbsd at virgilio.it
Mon Aug 1 11:56:29 GMT 2005
Dear Glenn,
even though a bit late here you are the info you suggested to check (still
absolutely obscure to me!!):
Yes, the / directory for booting is /dev/ad1s2a as in the fstab file.
>From dmesg:
ad0: 9541MB <WDC WD100BA/16.13M16> [19386/16/63] at ata0-master UDMA33
ad1: 9541MB <WDC WD200EB-11CPF0/06.04G06> [19386/16/63] at ata0-slave UDMA33
vicbsd root# fdisk /dev/ad0
******* Working on device /dev/ad0 *******
parameters extracted from in-core disklabel are:
cylinders=19386 heads=16 sectors/track=63 (1008 blks/cyl)
Figures below won't work with BIOS for partitions not in cyl 1
parameters to be used for BIOS calculations are:
cylinders=19386 heads=16 sectors/track=63 (1008 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 19541025 (9541 Meg), flag 80 (active)
beg: cyl 0/ head 1/ sector 1;
end: cyl 1023/ head 15/ sector 63
The data for partition 2 is:
<UNUSED>
The data for partition 3 is:
<UNUSED>
The data for partition 4 is:
<UNUSED>
vicbsd root# fdisk /dev/ad1
******* Working on device /dev/ad1 *******
parameters extracted from in-core disklabel are:
cylinders=19386 heads=16 sectors/track=63 (1008 blks/cyl)
Figures below won't work with BIOS for partitions not in cyl 1
parameters to be used for BIOS calculations are:
cylinders=19386 heads=16 sectors/track=63 (1008 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:
<UNUSED>
The data for partition 2 is:
sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
start 9179856, size 10361232 (5059 Meg), flag 80 (active)
beg: cyl 1023/ head 15/ sector 63;
end: cyl 1023/ head 15/ sector 63
The data for partition 3 is:
<UNUSED>
The data for partition 4 is:
<UNUSED>
vicbsd root# bsdlabel /dev/ad1s2
# /dev/ad1s2:
8 partitions:
# size offset fstype [fsize bsize bps/cpg]
a: 9312656 1048576 4.2BSD 2048 16384 28552
b: 1048576 0 swap
c: 10361232 0 unused 0 0 # "raw" part, don't
edit
vicbsd root# bsdlabel /dev/ad0s1
# /dev/ad0s1:
8 partitions:
# size offset fstype [fsize bsize bps/cpg]
a: 14336000 0 4.2BSD 0 0 0
b: 1084449 18456576 swap
c: 19541025 0 unused 0 0 # "raw" part, don't
edit
d: 524288 14336000 4.2BSD 2048 16384 32776
e: 524288 14860288 4.2BSD 2048 16384 32776
f: 3072000 15384576 4.2BSD 2048 16384 28552
Ciao
Vittorio
>-- Messaggio originale --
>Date: Fri, 29 Jul 2005 08:43:10 -0700
>To: Vittorio De Martino <vdm.fbsd at virgilio.it>
>From: Glenn Dawson <glenn at antimatter.net>
>Subject: Re: Problems with booting & MBR
>
>
>At 08:25 AM 7/29/2005, you wrote:
>>Friends,
>>as suggested in the docs in the internet I tried both with
>>
>>
>># fdisk -B -b /boot/boot0 ad0
>>fdisk: cannot open disk /dev/ad0: No such file or directory
>>
>>and with
>>
>>
>># fdisk -B -b /boot/boot0 ad1
>>fdisk: cannot open disk /dev/ad1: No such file or directory
>>
>>WHILST
>>my working /etc/fstab is, as I mentioned before:
>># Device Mountpoint FStype Options Dump
>Pass#
>>/dev/ad1s2b none swap sw 0
>0
>>/dev/ad1s2a / ufs rw 1
>1
>>/dev/ad0s1a /usr/local ufs rw 0
>0
>>/dev/ad0s1d /var ufs rw 0
>0
>>/dev/ad0s1e /tmp ufs rw 0
>0
>>
>>Why FreeBSD 5.4 cannot find /dev/ad0 and ad1?
>>What should I do?
>
>How are you booting the system to get to a prompt where you can issue the
>
>commands shown above?
>
>The first thing you probably need to do is examine dmesg output and see
>what disk devices are being detected at boot time. Then look in /dev and
>
>see if the entries you need are there or not.
>
>Also, one thing to keep in mind is that the bootloader only knows how to
>
>find the root file system when it's on the 'a' partition. Based on your
>
>fstab above, that would be /dev/ad1s2a. Assuming that's correct, what's
>on
>ad1s1?
>
>It would be helpful to see output from 'fdisk /dev/ad0' and 'fdisk
>/dev/ad1' if you can get it. Then depending on what slices are there, the
>
>corresponding bsdlabel output. Here's a sample from one of my test systems
>
>(it boots from /dev/ad4 which has two slices, one with 4.11 and one with
>
>5.4 installed)
>
>test54# fdisk /dev/ad4
>******* Working on device /dev/ad4 *******
>parameters extracted from in-core disklabel are:
>cylinders=387621 heads=16 sectors/track=63 (1008 blks/cyl)
>
>Figures below won't work with BIOS for partitions not in cyl 1
>parameters to be used for BIOS calculations are:
>cylinders=387621 heads=16 sectors/track=63 (1008 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 10474317 (5114 Meg), flag 80 (active)
> beg: cyl 0/ head 1/ sector 1;
> end: cyl 651/ head 254/ sector 63
>The data for partition 2 is:
>sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
> start 10474380, size 10458315 (5106 Meg), flag 0
> beg: cyl 652/ head 0/ sector 1;
> end: cyl 1023/ head 254/ sector 63
>The data for partition 3 is:
><UNUSED>
>The data for partition 4 is:
><UNUSED>
>
>And, the bsdlabel output from the two slices that are shown above:
>
>test54# bsdlabel /dev/ad4s1
># /dev/ad4s1:
>8 partitions:
># size offset fstype [fsize bsize bps/cpg]
> a: 524288 0 4.2BSD 2048 16384 32776
> b: 2038416 524288 swap
> c: 10474317 0 unused 0 0 # "raw" part,
>don't edit
> d: 524288 2562704 4.2BSD 2048 16384 32776
> e: 524288 3086992 4.2BSD 2048 16384 32776
> f: 6863037 3611280 4.2BSD 2048 16384 28552
>
>
>test54# bsdlabel /dev/ad4s2
># /dev/ad4s2:
>8 partitions:
># size offset fstype [fsize bsize bps/cpg]
> a: 262144 0 4.2BSD 0 0 0
> c: 10458315 0 unused 0 0 # "raw" part,
>don't edit
> e: 524288 262144 4.2BSD 0 0 0
> f: 524288 786432 4.2BSD 0 0 0
> g: 9147595 1310720 4.2BSD 0 0 0
>
>
>Once you know where things actually are on the disks you have, it'll be
a
>
>lot easier to figure out what needs to be done in order to have it boot
>correctly.
>
>-Glenn
>
>
>
>
>>A baffled and frustated Vittorio again
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