Hello all.
I am in need of a little help or advice to rescue an OpenBSD server I do
not have physical access to. I have or can have a KVM but no iso remote
loading/booting. I can use a "PXE linux boot disk" to do basic disc /
Slice changes. The server was installed using a custom procedure
similar to yafoo.
The setup
---------
I set up the computer disk with two slices (what dos call partitions,
the one that are limited to 4 primary ones to get the terminology
right), BOTH of them having OpenBSD, the fist one of 1G contains a
"rescue" OBSD and the other one contains the "main/ productive" Openbsd.
To achieve this I installed one slice, hidden it as a Opus (code 10)
partition type and installed another OpenBSD on the other slice.
The disk layout is as such
fdisk wd0
Disk: wd0 geometry: 19457/255/63 [312581808 Sectors]
Offset: 0 Signature: 0xAA55
Starting Ending LBA Info:
#: id C H S - C H S [ start: size ]
------------------------------------------------------------------------
0: 10 0 1 1 - 100 254 63 [ 63: 1622502 ] OPUS
*1: A6 101 0 1 - 19456 254 63 [ 1622565: 310954140 ] OpenBSD
2: 00 0 0 0 - 0 0 0 [ 0: 0 ] unused
3: 00 0 0 0 - 0 0 0 [ 0: 0 ] unused
The first Opus(10) partition is in fact an openbsd install. I switch
between the two by making the slice 0 active putting its os code at
openBSD(A6) and putting the slice 2 at OS code Opus(10). I was probably
too smart for my own good at the time. :)
The problem
-----------
Since a few days I was not able to access the machine. A ram hardware
failure was diagnosed and ram changed but I still was not able to boot
on the main partition on slice 1.
===============================================================
A KWM showed a failure at boot time of the "ERR M " kind ...
===============================================================
I looked it up and understand that it is linked to boot(8) being
corrupt and not knowing were to look for the kernel. Installboot should
be a solution but I don't know how to run it in my situation.
I have acces and can boot on the "rescue" slice 0 partition but running
installboot from it won't give me the desired result since it would link
the "boot(8)" record to the slice 0 kernel and not the slice 1 kernel.
"Questions"
----------
Question 1
Is it possible to do that ? i.e. reinstall the boot(8) bloc on slice 1
refering to the slice 1 kernel on that partition ?
To me it means being able to mount the slice 1 frome slice 0 no ?
witch lead the to my second question
Question 2
Either to recue the slice 1 setup or to retrieve my datas, how can I
make the slice 1 seen and mount it from slice 0 ? I have record of the
exact layout of both slices. Currently disklabel from slice 0 show me
that :
# disklabel wd0
# Inside MBR partition 0: type A6 start 63 size 1622502
# /dev/rwd0c:
type: ESDI
disk: ESDI/IDE disk
label: ST3160812AS
flags:
bytes/sector: 512
sectors/track: 63
tracks/cylinder: 255
sectors/cylinder: 16065
cylinders: 19457
total sectors: 312581808
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0 # microseconds
track-to-track seek: 0 # microseconds
drivedata: 0
16 partitions:
# size offset fstype [fsize bsize cpg]
a: 1333332 63 4.2BSD 2048 16384 1
b: 289170 1333395 swap
c: 312581808 0 unused 0 0
i: 310954140 1622565 unknown
Obviously the i partition is the whole slice 1.
I want to make it so
16 partitions:
# size offset fstype [fsize bsize cpg]
a: 4194307 1622565 4.2BSD 2048 16384 1
b: 4194304 5816872 swap
c: 312581808 0 unused 0 0
d: 4194304 10011176 4.2BSD 2048 16384 1
e: 62914560 14205480 4.2BSD 2048 16384 1
g: 62914560 77120040 4.2BSD 2048 16384 1
h: 125829120 140034600 4.2BSD 2048 16384 1
Since I recorded the layout of the slice 1 when configuring the machine.
Is it the right thing to do from disklabel from the slice 0 openBSD ?
Would there be some adverse effect from doing it on my slice 1 datas ?
Am I right in my understanding that is will only change my slice 0
disklabel, giving it knowledge of the slice 1 layout but not write
anything on the slice 1 ?
Question 3
Anybody would have a bright idea of a solution or things to do that
would have escaped my limited mind ? I am open to any pointer or
suggestion before doing some irreparable harm to my disks.
Thanks a lot for your time and help anyway and thanks for helping make
OpenBSD the OS it is...
Aditionnal datas
----------------
Original slice 0 layout :
# disklabel wd0
# Inside MBR partition 0: type A6 start 63 size 1622502
# /dev/rwd0c:
type: ESDI
disk: ESDI/IDE disk
label: ST3160812AS
flags:
bytes/sector: 512
sectors/track: 63
tracks/cylinder: 255
sectors/cylinder: 16065
cylinders: 19457
total sectors: 312581808
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0 # microseconds
track-to-track seek: 0 # microseconds
drivedata: 0
16 partitions:
# size offset fstype [fsize bsize cpg]
a: 1333332 63 4.2BSD 2048 16384 1
b: 289170 1333395 swap
c: 312581808 0 unused 0 0
i: 310954140 1622565 unknown
Original slice 1 layout :
>disklabel wd0
# Inside MBR partition 1: type A6 start 1622565 size 310954140
# /dev/rwd0c:
type: ESDI
disk: yaifo
label:
flags:
bytes/sector: 512
sectors/track: 4
tracks/cylinder: 2
sectors/cylinder: 8
cylinders: 768
total sectors: 312581808
rpm: 300
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0 # microseconds
track-to-track seek: 0 # microseconds
drivedata: 0
16 partitions:
# size offset fstype [fsize bsize cpg]
a: 4194307 1622565 4.2BSD 2048 16384 1
b: 4194304 5816872 swap
c: 312581808 0 unused 0 0
d: 4194304 10011176 4.2BSD 2048 16384 1
e: 62914560 14205480 4.2BSD 2048 16384 1
g: 62914560 77120040 4.2BSD 2048 16384 1
h: 125829120 140034600 4.2BSD 2048 16384 1
