Changed names of logical disks on recent -CURRENT: part
of logical disks not accessible now
Marcel Moolenaar
xcllnt at mac.com
Sat Jan 3 16:30:12 UTC 2009
On Dec 31, 2008, at 7:16 PM, Jos Backus wrote:
> Hi Marcel,
>
> On Mon, Dec 29, 2008 at 10:11:03PM -0800, Marcel Moolenaar wrote:
>> I've seen this before: Erase the second sector on your
>> disk. You likely have a stale BSD disklabel there.
>
> Before I start erasing, does this look like something that can be
> erased
> safely?
>
> lizzy:~# dd if=/dev/ad0 count=1 skip=1 | hexdump -C
> 1+0 records in
> 1+0 records out
> 512 bytes transferred in 0.009828 secs (52096 bytes/sec)
> 00000000 57 45 56 82 00 00 00 00 61 6d 6e 65 73 69 61 63 |
> WEV.....amnesiac|
> 00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> |................|
> 00000020 00 00 00 00 00 00 00 00 00 02 00 00 3f 00 00 00
> |............?...|
> 00000030 10 00 00 00 15 ed 12 00 f0 03 00 00 b0 82 85 4a
> |...............J|
> 00000040 00 00 00 00 00 00 00 00 10 0e 01 00 00 00 00 00
> |................|
> 00000050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> |................|
> *
> 00000080 00 00 00 00 57 45 56 82 a8 07 08 00 00 20 00 00
> |....WEV...... ..|
> 00000090 00 00 00 00 00 00 20 00 10 00 00 00 00 08 00 00
> |...... .........|
> 000000a0 07 08 88 6f 00 00 80 00 10 00 20 00 00 00 00 00
> |...o...... .....|
> 000000b0 01 00 00 00 b0 82 85 4a 00 00 00 00 00 00 00 00
> |.......J........|
> 000000c0 00 00 00 00 00 00 20 00 10 00 a0 00 00 08 00 00
> |...... .........|
> 000000d0 07 08 88 6f 00 00 00 04 10 00 c0 00 00 08 00 00
> |...o............|
> 000000e0 07 08 88 6f a0 82 c5 45 10 00 c0 04 00 08 00 00
> |...o...E........|
> 000000f0 07 08 88 6f 00 00 00 00 00 00 00 00 00 00 00 00
> |...o............|
> 00000100 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> |................|
> *
> 00000200
>
> Or do you mean /dev/ad0s1? (I thought disklabels generally sit
> inside fdisk
> partitions^Wslices.)
>
> lizzy:~# dd if=/dev/ad0s1 count=1 skip=1 | hexdump -C
> 1+0 records in
> 1+0 records out
> 512 bytes transferred in 0.016460 secs (31105 bytes/sec)
> 00000000 57 45 56 82 00 00 00 00 61 6d 6e 65 73 69 61 63 |
> WEV.....amnesiac|
> 00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> |................|
> 00000020 00 00 00 00 00 00 00 00 00 02 00 00 3f 00 00 00
> |............?...|
> 00000030 10 00 00 00 14 ed 12 00 f0 03 00 00 71 82 85 4a
> |............q..J|
> 00000040 00 00 00 00 00 00 00 00 10 0e 01 00 00 00 00 00
> |................|
> 00000050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> |................|
> *
> 00000080 00 00 00 00 57 45 56 82 68 07 08 00 00 20 00 00
> |....WEV.h.... ..|
> 00000090 00 00 00 00 00 00 20 00 10 00 00 00 00 08 00 00
> |...... .........|
> 000000a0 07 08 88 6f 00 00 80 00 10 00 20 00 00 00 00 00
> |...o...... .....|
> 000000b0 01 00 00 00 71 82 85 4a 00 00 00 00 00 00 00 00
> |....q..J........|
> 000000c0 00 00 00 00 00 00 20 00 10 00 a0 00 00 08 00 00
> |...... .........|
> 000000d0 07 08 88 6f 00 00 00 04 10 00 c0 00 00 08 00 00
> |...o............|
> 000000e0 07 08 88 6f 61 82 c5 45 10 00 c0 04 00 08 00 00
> |...oa..E........|
> 000000f0 07 08 88 6f 00 00 00 00 00 00 00 00 00 00 00 00
> |...o............|
> 00000100 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> |................|
> 00000110 00 00 00 00 eb 0e 42 54 58 01 02 80 f6 0f 80 06
> |......BTX.......|
> 00000120 00 20 00 00 fa 31 c0 8e d0 bc 00 18 8e c0 8e d8 |. ...
> 1..........|
> 00000130 66 6a 02 66 9d bf 00 5e b9 00 19 f3 ab bb 22 95 |
> fj.f...^......".|
> 00000140 b9 10 00 bf 80 00 89 1d 47 47 ab 83 c3 04 e2 f6
> |........GG......|
> 00000150 bf 00 5e be d2 95 ac 98 91 e3 1d ac 92 ad 93 ad
> |..^.............|
> 00000160 b6 08 d1 eb 73 0b 89 05 88 75 02 88 55 05 83 c0
> |....s....u..U...|
> 00000170 04 8d 7d 08 e2 ec eb de c6 45 05 18 c6 45 08 10
> |..}......E...E..|
> 00000180 c6 45 66 68 bb 20 28 e8 b8 00 0f 01 1e c6 95 0f |.Efh.
> (.........|
> 00000190 01 16 c0 95 0f 20 c0 40 0f 22 c0 ea 8c 90 08 00
> |..... . at ."......|
> 000001a0 31 c9 b1 10 8e d1 b1 38 0f 00 d9 ba 00 a0 00 00 |
> 1......8........|
> 000001b0 36 0f b7 05 13 04 00 00 c1 e0 0a 2d 00 10 00 00 |
> 6..........-....|
> 000001c0 29 d0 b1 33 51 50 68 02 02 00 00 6a 2b ff 35 0c |)..
> 3QPh....j+.5.|
> 000001d0 90 00 00 51 51 51 51 52 b1 07 6a 00 e2 fc 61 07
> |...QQQQR..j...a.|
> 000001e0 1f 0f a1 0f a9 cf fa bc 00 18 00 00 0f 20 c0 25
> |............. .%|
> 000001f0 ff ff ff 7f 0f 22 c0 31 c9 0f 22 d9 0f 01 15 c0 |.....".
> 1..".....|
> 00000200
>
> Thanks and Happy New Year!
Hi Jos,
"dd if=/dev/zero of=/dev/ad0 count=1 oseek=1" is what you
need. As you say, the BSD disklabel lives in the slice,
so the one in sector 1 (counting from 0) is the stale one
and the one preventing you from booting.
Happy New Year to you (and Trish) too,
--
Marcel Moolenaar
xcllnt at mac.com
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