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Volume Group with 4 HDs- one crashed

linux-lvm nik-da-3'9'' 2 participants 3 messages Jan 10, 2003

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#0 lore raw

Hello ,

I'm having a hard time with LVM, in my PC I have setup a VG with 4 harddisks, and one of the HDs crashed. Well, I know I should have backed up the data,
which I did, but the backup is far too old. You know how hard it is to backup big big HDs/partitions w/o having bunches of backup media. Anyway, I have consulted Heinz, who was so kind pointing to LVM2, with its help it should have been possible to mount the VG partially. What I did was:

1. upgrade my kernel, so I could use the device-mapper, which is important for LVM2
2. installed LVM2
3. tried "vgchange -P -ay", which gave me following output:

Quoted 22 lines

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3 logical volume(s) in volume group "data" now active
Finding volume group "mpeg"
3 PV(s) found for VG mpeg: expected 4
Logical volume (mp3) contains an incomplete mapping table.
2 logical volume(s) in volume group "mpeg" already active
3 PV(s) found for VG mpeg: expected 4
Logical volume (mp3) contains an incomplete mapping table.
Found volume group "mpeg"
3 PV(s) found for VG mpeg: expected 4
Logical volume (mp3) contains an incomplete mapping table.
Found volume group "mpeg"
3 PV(s) found for VG mpeg: expected 4
Logical volume (mp3) contains an incomplete mapping table.
Found volume group "mpeg"
3 PV(s) found for VG mpeg: expected 4
Logical volume (mp3) contains an incomplete mapping table.
Found volume group "mpeg"
Activated logical volumes in volume group "mpeg"
2 logical volume(s) in volume group "mpeg" now active
----

Quoted 6 lines

vgdisplay :
Finding volume group "mpeg"
3 PV(s) found for VG mpeg: expected 4
Volume group "mpeg" doesn't exist

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even vgscan did not help:

: # LVM2.1.95.12/tools/lvm vgscan -v
Wiping cache of LVM-capable devices
Wiping internal cache
Reading all physical volumes. This may take a while...
Finding all volume groups
Finding volume group "data"
Found volume group "data" using metadata type lvm1
Finding volume group "mpeg"
3 PV(s) found for VG mpeg: expected 4
Volume group "mpeg" not found

: # mount -a
mount: special device /dev/mpeg/mp3 does not exist
mount: special device /dev/mpeg/movie does not exist

VG "data" is a VG on different SCSI-HDs (which is backed up on a reg basis... anyway this VG was never touched, as it didnt crash).

I also remove the devnodes left by LVM 1 (/dev/mpeg/mp3 /dev/mpeg/mpvie), but still I cant access the VG's.

What to do next? Any help is really appreciated, as there is still lots of important data on the VGs.

Thanks

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Regards,
 nik-da-3'9''
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#1 lore raw
Quoted 1 line · On Fri, Jan 10, 2003 at 02:38:35PM +0100, nik-da-3'9'' wrote:
Quoted 1 line

2 logical volume(s) in volume group "mpeg" now active

So did that not activate 2 of the logical volumes?

You have to add '-P' to *every* tool that you want to attempt to use volume groups that are Partially missing. (But tools only support the flag where it makes sense to.)

Quoted 1 line

Found volume group "data" using metadata type lvm1

So it found that OK.

Quoted 2 lines

I also remove the devnodes left by LVM 1 (/dev/mpeg/mp3 /dev/mpeg/mpvie), but still I cant access the VG's.

Recent LVM2 tarballs deal OK with any nodes left behind like that. What version are you using?

Quoted 2 lines

What to do next? Any help is really appreciated, as there is still lots of important data on the VGs.

Read the -P section of 'man lvm' for extra hints on recovery: depends if you're able to replace the disk with another, or if you want to remove the disk from the VG completely.

See also the thread a few days back:
Re: [linux-lvm] problem

Alasdair

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#2 lore raw
Quoted 4 lines · Alasdair Kergon
Quoted 2 lines

I also remove the devnodes left by LVM 1 (/dev/mpeg/mp3 /dev/mpeg/mpvie), but still I cant access the VG's.

Recent LVM2 tarballs deal OK with any nodes left behind like that. What version are you using?

Ah you said: .12
That change went into .13

vgdisplay wouldn't show them because you didn't add -P

Do a 'vgchange -an -P' and then try activating them again.

Try 'lvdisplay -P' to check if they're active, or check the attr. columns (see man page) in the new 'lvs -P' command.

Alasdair

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