Subject: disklabel: can't read master boot record
To: None <netbsd-users@netbsd.org>
From: Zafer Aydogan <zafer@gmx.org>
List: netbsd-users
Date: 11/30/2004 16:37:28
Hej Mailing-List,

I added two new disks to my system.

wd2 and sd0

disklabel produces this error:

# disklabel -i /dev/wd2
disklabel: can't read master boot record: Undefined error: 0
disklabel: ioctl DIOCGDINFO: Inappropriate ioctl for device

the other disk:
# fdisk  /dev/sd0
Disk: /dev/sd0d
NetBSD disklabel disk geometry:
cylinders: 8188 heads: 3 sectors/track: 172 (516 sectors/cylinder)

BIOS disk geometry:
cylinders: 263 heads: 255 sectors/track: 63 (16065 sectors/cylinder)

Partition table:
0: sysid 165 (FreeBSD or 386BSD or old NetBSD)
    start 63, size 4225032 (2063 MB), flag 0x80
        beg: cylinder    0, head   1, sector  1
        end: cylinder  262, head 254, sector 63
1: <UNUSED>
2: <UNUSED>
3: <UNUSED>

# disklabel -i /dev/sd0
disklabel: old BSD partition ID!
partition>P
16 partitions:
#        size    offset     fstype  [fsize bsize cpg/sgs]
 a:   4226725         0     4.2BSD   2048 16384 28552   # (Cyl.    0 - 263*)
 d:   4226725         0     unused      0     0         # (Cyl.    0 - 263*)
partition>Q
# newfs /dev/sd0a
With 16065 sectors per cylinder, minimum cylinders per group is 64
This requires the block size to be changed from 16384 to 32768
        and the fragment size to be changed from 2048 to 4096

# newfs -b 32768 -f 4096 /dev/sd0a
Warning: insufficient space in super block for
 rotational layout tables with nsect 63 and ntrak 255.
File system performance may be impaired.
Warning: 14440 sector(s) in last cylinder unallocated
/dev/sd0a:      4226720 sectors in 264 cylinders of 255 tracks, 63 sectors
        2063.8MB in 5 cyl groups (64 c/g, 502.03MB/g, 26368 i/g)
super-block backups (for fsck -b #) at:
      64, 1028288, 2056512, 3084736, 4112960,
wtfs: write error for sector 16: Read-only file system
#
Huh ?
Any Ideas ?
How do I write a new Masterbootrecord on my Disk wd2 ?

system is i386/1.6.1
$ mount
/dev/wd0a on / type ffs (soft dependencies, local)
/dev/wd0e on /usr type ffs (soft dependencies, local)
/dev/wd1a on /usr/ekssich type ffs (soft dependencies, local)
/dev/wd3a on /usr/ftp/pub/NetBSD type ffs (soft dependencies, local)

Regards, Zafer.