Hello!
Here is a summary of a thread I started on comp.unix.bsd.freebsd.misc to no
avail. I hope someone will be able to give me some advice here
I've installed FreeBSD 5.0 on the second disk of my PC where I had an old 4.5
working.
Unfortunately the install process failed to write the MBR correctly and with
the current BootMgr, I can not boot on the FreeBSD disk.
I've booted with a floppy and re-run sysinstall. I've tried to mark ad2s2 as
bootable but just got:
ERROR: Unable to write data to disk ad2!
Disk partition write returned an error status!
I think it is related to what is written in the FreeBSD
5.0-RELEASE Errata about disklabel -B:
The geom(4)-based disk
partitioning code in the kernel will not allow an open
partition to be overwritten. This usually prevents the use
of disklabel -B to update the boot
blocks on a disk because the a partition overlaps the space where the boot
blocks are
stored. A suggested workaround is to boot from an alternate
disk, a CDROM, or a fixit floppy.
But the workaround does not seem to be efficient with my box. I don't get the
previous error message when I mark the second disk as bootable with
sysinstall/fdisk, but I still can not boot from it.
The output of fdisk ad2 is as follows:
-
*** Working on device /dev/ad2 ***
parameters extracted from in-core disklabel are:
cylinders=19852 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=19852 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 5 (0x05),(Extended DOS)
start 16065, size 4176900 (2039 Meg), flag 0
beg: cyl 15/ head 15/ sector 1;
end: cyl 1023/ head 10/ sector 63
The data for partition 2 is:
sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
start 4192965, size 15807960 (7718 Meg), flag 80 (active)
beg: cyl 1023/ head 255/ sector 63;
end: cyl 1023/ head 2/ sector 63
The data for partition 3 is:
UNUSED
The data for partition 4 is:
UNUSED
-
The problem seems that the number of cylinders is not equal to the one
displayed in the BIOS setup: 16320.
If I force this geometry value with fdisk via sysinstall, will I have to
reinstall completely the system?
Here is the output from boot0cfg -v ad0:
-
# flag start chs type end chs offset size
1 0x80 0: 1: 1 0x06618: 63:63 63 2495745
version=1.0 drive=0x80 mask=0xf ticks=182
options=nopacket,update,nosetdrv
default_selection=F1 (Slice 1)
-
and the output from boot0cfg -v ad2:
-
# flag start chs type end chs offset size
1 0x00 15: 15: 1 0x05 1023: 10:6316065 4176900
2 0x80 1023:255:63 0xa5 1023: 2:63 4192965 15807960
version=1.0 drive=0x82 mask=0xf ticks=182
options=nopacket,update,nosetdrv
default_selection=F5 (Drive 1)
-
According to the manual, I may use the 'packet' option of boot0cfg since I
have
to boot above cylinder 1023, but my BIOS does not seem to be compatible with
this option.
What can I do? Do I have to go through the process of creating a
dangerously-dedicated slice?
I had no problem to boot on this disk with FreeBSD 4.x.
BTW, here's the ouput of disklabel ad2s2:
-
# /dev/ad2s2c:
type: ESDI
disk: ad2s2
label:
flags:
bytes/sector: 512
sectors/track: 63
tracks/cylinder: 16
sectors/cylinder: 1008
cylinders: 19852
sectors/unit: 20010816
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0 # milliseconds
track-to-track seek: 0 # milliseconds
drivedata: 0
8 partitions:
#size offsetfstype [fsize bsize bps/cpg]
a: 52428804.2BSD 2048 16384 32776 # (Cyl.0 -
520*)
b: 362176 524288 swap # (Cyl. 520*- 879*)
c: 158079600unused0 0# (Cyl.0 -15682*)
d: 524288 8864644.2BSD 2048 16384 32776 # (Cyl. 879*-1399*)
e: 524288 14107524.2BSD 2048 16384 32776 # (Cyl. 1399*-1919*)
f: 13872920 19350404.2BSD 2048 16384 28512 # (Cyl. 1919*-15682*)
Warning, partition c doesn't cover the whole unit!
Warning, An incorrect partition c may cause problems for standard system
utilities
-
and with the -r option, disklabel -r ad2s2:
