[linux-lvm] f*cked up metadata on 1of3 LVM-disks
Jayson Vantuyl
jvantuyl at engineyard.com
Mon May 21 16:27:33 UTC 2007
BigMac,
Okay, I think I have a solution, but it's your data, so beware.
First force the VG to activated. To do this, use the -P flag
(partial). It will activate as much of the VG as it can find. So,
first:
vgscan -P
vgchange -ay -P vgdata
Then, get a backup of the metadata:
vgcfgbackup -f vgdata.lvm -P vgdata
Now, recreate the PV metadata on the damaged disk, just to get the
UUID back:
pvcreate -ff -u 9kpWwu-LdwT-YiqV-DRPg-kSAN-plYN-v1Eq81 /dev/hdc
Now you should have the pv there but with inconsistent metadata.
Now, restore the metadata from the backup we just made:
vgcfgrestore -f vgdata.lvm vgdata
If the planets are aligned and you are very lucky, you might have
your LV back. Good luck, and I'm curious if this will actually work.
On May 21, 2007, at 8:57 AM, Dave Wysochanski wrote:
> On Mon, 2007-05-21 at 12:38 +0200, BigMac wrote:
>> Nobody an idea how to recover the lvm meta data on the disk?
>> The data itself an the other disks are fine, just the first
>> sectors of
>> /dev/hdc are gone by installing grub on it.
>>
>> I had a deeper look on the disk with one of those low level disk
>> editors
>> and there are still parts of the meta-data stored on the disk.
>> It seems to be that grub messed up just the first 17 sectors of
>> the disk.
>>
>> Regards,
>>
>> BigMac
>>
>
> I am working on a tool to do recovery and pull metadata out of the
> disks. Maybe this will help you.
>
> You can try "pvck -v" in the latest upstream LVM code. It does not
> extract metadata to a file yet but makes an attempt at identifying
> areas
> on the disk that contain metadata and prints the offsets and lengths
> (you can then just dd to a file). Since you have other PVs that are
> valid you could at least get the latest metadata off one of those,
> then
> use vgcfgrestore with this file and uuid option.
>
> Also, can you send me the first 256K? Something like:
> dd if=/dev/hdc of=/tmp/file.raw bs=1024 count=256 and send
> me /tmp/file.raw in an email attachment?
>
> Maybe I can enhance the extraction and/or add this case to my unit
> test.
> Ideas on enhancements welcome.
>
>
>
>>
>>
>> BigMac schrieb:
>>> Hi lists!
>>>
>>> My fileserver stored it's data on 3 physical disks,building a
>>> volumegroup with lvm2.
>>> The mashine was running ubuntu dapper drake for a long time
>>> without any
>>> problems but I decided to switch to ubuntu feisty fawn. Switching
>>> from
>>> debian to dapper drake I installed and removed quite a lot of
>>> packages,
>>> leaving a messy system, so I thought a new and clean installation
>>> with
>>> feisty fawn might be a great idea.
>>>
>>> box config with dapper drake:
>>>
>>> hda: 120GB (PATA) systemdisk
>>> hdb: unused
>>> hdc: 250GB (PATA) part of the LVM-array
>>> hdd: 250GB (PATA) part of the LVM-array
>>> sda: 400GB (SATA) part of the LVM-array
>>> sdb: DVD-RW (PATA on additional PCI-controller UDMA-100)
>>>
>>> The additional IDE-controller was installed to be able to install
>>> even
>>> more disks, but as I won't buy any new PATA stuff the controller was
>>> dispensable.
>>>
>>> new box config:
>>>
>>> hda: 120GB (PATA) systemdisk
>>> hdb: DVD-RW
>>> hdc: 250GB (PATA) part of the LVM-array
>>> hdd: 250GB (PATA) part of the LVM-array
>>> sda: 400GB (SATA) part of the LVM-array
>>>
>>> I exported the vg before shutting down dapper drake and while
>>> installing
>>> festy fawn to the box I - no idea what did me do so - installed
>>> grub to
>>> hdc. Ooops, this disk was part of the LVM array and so grub
>>> f*cked up
>>> the lvm meta-data on hdc.
>>>
>>> After installing grub to hda the box is running fine, despite the
>>> LVM
>>> which can't find one of the vgs volumes:
>>>
>>> Code:
>>>
>>> bigmac at knecht:~$ sudo pvscan
>>> Couldn't find device with uuid '9kpWwu-LdwT-YiqV-DRPg-kSAN-plYN-
>>> v1Eq81'.
>>> Couldn't find device with uuid '9kpWwu-LdwT-YiqV-DRPg-kSAN-plYN-
>>> v1Eq81'.
>>> Couldn't find device with uuid '9kpWwu-LdwT-YiqV-DRPg-kSAN-plYN-
>>> v1Eq81'.
>>> Couldn't find device with uuid '9kpWwu-LdwT-YiqV-DRPg-kSAN-plYN-
>>> v1Eq81'.
>>> PV /dev/hdd VG vgdata lvm2 [232.88 GB / 0 free]
>>> PV unknown device VG vgdata lvm2 [232.88 GB / 0 free]
>>> PV /dev/sda VG vgdata lvm2 [372.61 GB / 4.00 MB free]
>>> Total: 3 [838.38 GB] / in use: 3 [838.38 GB] / in no VG: 0 [0 ]
>>>
>>> bigmac at knecht:~$ sudo pvdisplay
>>> Couldn't find device with uuid '9kpWwu-LdwT-YiqV-DRPg-kSAN-plYN-
>>> v1Eq81'.
>>> Couldn't find device with uuid '9kpWwu-LdwT-YiqV-DRPg-kSAN-plYN-
>>> v1Eq81'.
>>> Couldn't find device with uuid '9kpWwu-LdwT-YiqV-DRPg-kSAN-plYN-
>>> v1Eq81'.
>>> Couldn't find device with uuid '9kpWwu-LdwT-YiqV-DRPg-kSAN-plYN-
>>> v1Eq81'.
>>> --- Physical volume ---
>>> PV Name /dev/hdd
>>> VG Name vgdata
>>> PV Size 232.88 GB / not usable 0
>>> Allocatable yes (but full)
>>> PE Size (KByte) 4096
>>> Total PE 59618
>>> Free PE 0
>>> Allocated PE 59618
>>> PV UUID locW5S-HNFK-b1WW-iOLt-olHl-2SNd-fmXKC8
>>>
>>> --- Physical volume ---
>>> PV Name unknown device
>>> VG Name vgdata
>>> PV Size 232.88 GB / not usable 0
>>> Allocatable yes (but full)
>>> PE Size (KByte) 4096
>>> Total PE 59618
>>> Free PE 0
>>> Allocated PE 59618
>>> PV UUID 9kpWwu-LdwT-YiqV-DRPg-kSAN-plYN-v1Eq81
>>>
>>> --- Physical volume ---
>>> PV Name /dev/sda
>>> VG Name vgdata
>>> PV Size 372.61 GB / not usable 0
>>> Allocatable yes
>>> PE Size (KByte) 4096
>>> Total PE 95388
>>> Free PE 1
>>> Allocated PE 95387
>>> PV UUID YUJcsF-3XP7-OrbO-pITp-5z96-gw1A-DI11QS
>>>
>>>
>>> bigmac at knecht:~$ sudo vgscan
>>> Reading all physical volumes. This may take a while...
>>> Couldn't find device with uuid '9kpWwu-LdwT-YiqV-DRPg-kSAN-plYN-
>>> v1Eq81'.
>>> Couldn't find all physical volumes for volume group vgdata.
>>> Couldn't find device with uuid '9kpWwu-LdwT-YiqV-DRPg-kSAN-plYN-
>>> v1Eq81'.
>>> Couldn't find all physical volumes for volume group vgdata.
>>> Couldn't find device with uuid '9kpWwu-LdwT-YiqV-DRPg-kSAN-plYN-
>>> v1Eq81'.
>>> Couldn't find all physical volumes for volume group vgdata.
>>> Couldn't find device with uuid '9kpWwu-LdwT-YiqV-DRPg-kSAN-plYN-
>>> v1Eq81'.
>>> Couldn't find all physical volumes for volume group vgdata.
>>> Volume group "vgdata" not found
>>>
>>> I tried multiple Live-CDs like gparted (with testdisk), Ultimate
>>> Boot-CD
>>> and SystemRescueCd, but none could help.
>>>
>>> Any idea what to do to get the lvm up and running?
>>> How to restore the metadata on hdc?
>>>
>>> Best Regards,
>>>
>>> BigMac
>>>
>>> _______________________________________________
>>> linux-lvm mailing list
>>> linux-lvm at redhat.com
>>> https://www.redhat.com/mailman/listinfo/linux-lvm
>>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>>
>>>
>>
>> _______________________________________________
>> linux-lvm mailing list
>> linux-lvm at redhat.com
>> https://www.redhat.com/mailman/listinfo/linux-lvm
>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm at redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
--
Jayson Vantuyl
Systems Architect
Engine Yard
jvantuyl at engineyard.com
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