bypassing gmirror to recover filesystems

[Joan Picanyol i Puig]

El diu 04 de 03 del 2007 a les 23:21 +0100, en/na Joan Picanyol i Puig
va escriure:
> Hi,
> 
> I've been hit by kern/107315 (previously discussed
> http://lists.freebsd.org/pipermail/freebsd-geom/2006-April/001217.html)
> 
> Any suggestions?

What I did:

1.- boot old kernel, unloading geom_mirror first
2.- mount & dump all fs's (easy enough thanks to gmirror's metadata
being on the last sector)
3.- manually clear gmirror's metadata with dd
4.- repartition drives and setup gmirror again

I'm attaching the conflicting configuration (two mirrors on two slices,
the failing one without being bsdlabel'd).

qvb
--
pica
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******* Working on device /dev/ad4 *******
parameters extracted from in-core disklabel are:
cylinders=484521 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=484521 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 123715809 (60408 Meg), flag 80 (active)
	beg: cyl 0/ head 1/ sector 1;
	end: cyl 1023/ head 243/ sector 63
The data for partition 2 is:
sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
    start 123715872, size 307195623 (149997 Meg), flag 0
	beg: cyl 1023/ head 255/ sector 63;
	end: cyl 1023/ head 254/ sector 63
The data for partition 3 is:
<UNUSED>
The data for partition 4 is:
<UNUSED>
-------------- next part --------------
# /dev/ad4s1:
8 partitions:
#        size   offset    fstype   [fsize bsize bps/cpg]
  a:  1048576        0    4.2BSD        0     0     0 
  c: 123715809        0    unused        0     0         # "raw" part, don't edit
  d:  1048576  1048576    4.2BSD        0     0     0 
  e: 10485760  2097152    4.2BSD        0     0     0 
  f:  2097152 12582912    4.2BSD        0     0     0 
  g:  4194304 14680064    4.2BSD        0     0     0 
  h: 104841440 18874368    4.2BSD        0     0     0 
-------------- next part --------------
# /dev/ad4s2:
8 partitions:
#        size   offset    fstype   [fsize bsize bps/cpg]
  c: 307195623        0    unused        0     0         # "raw" part, don't edit
-------------- next part --------------
Geom name: gm0s1
State: COMPLETE
Components: 2
Balance: round-robin
Slice: 4096
Flags: NONE
GenID: 0
SyncID: 1
ID: 2494591388
Providers:
1. Name: mirror/gm0s1
   Mediasize: 63342493696 (59G)
   Sectorsize: 512
   Mode: r6w6e7
Consumers:
1. Name: ad4s1
   Mediasize: 63342494208 (59G)
   Sectorsize: 512
   Mode: r1w1e1
   State: ACTIVE
   Priority: 0
   Flags: DIRTY, HARDCODED
   GenID: 0
   SyncID: 1
   ID: 2375384516
2. Name: ad6s1
   Mediasize: 63342494208 (59G)
   Sectorsize: 512
   Mode: r1w1e1
   State: ACTIVE
   Priority: 0
   Flags: DIRTY, HARDCODED
   GenID: 0
   SyncID: 1
   ID: 1585998909

Geom name: gm1
State: COMPLETE
Components: 2
Balance: split
Slice: 4096
Flags: NONE
GenID: 0
SyncID: 1
ID: 947166852
Providers:
1. Name: mirror/gm1
   Mediasize: 157284158464 (146G)
   Sectorsize: 512
   Mode: r0w0e0
Consumers:
1. Name: ad4s2
   Mediasize: 157284158976 (146G)
   Sectorsize: 512
   Mode: r1w1e1
   State: ACTIVE
   Priority: 0
   Flags: HARDCODED
   GenID: 0
   SyncID: 1
   ID: 2563999181
2. Name: ad6s2
   Mediasize: 157284158976 (146G)
   Sectorsize: 512
   Mode: r1w1e1
   State: ACTIVE
   Priority: 1
   Flags: HARDCODED
   GenID: 0
   SyncID: 1
   ID: 3562666656