Re: Recovering "broken" disk ( 17th )

Roger Heflin <[email protected]>
Newsgroups gmane.linux.lvm.general
Message-ID <CAAMCDedrphwa+RRr1PHLD0SXi8fEDM87zV82302T=twRa5qBZA@mail.gmail.com>
You will need a lvm backup file for the pvcreate --uuid I believe (there
may be some option to get around needing the backup file).

That will put the header back on if you either have an lvm backup and/or
archive file, you might also need a vgcfgrestore afterwards depending on if
anything else is missing.

I have never done it, but it looks possible to make a lvm backup file by
reading it directly off the disk with dd, so that you will have a file that
pvcreate is ok with, that is if there is no way to force it without a
backup file.

But, this should get the pv back showing up with whatever sectors that you
successfully recovered.

On Sun, Oct 17, 2021 at 10:02 PM Brian McCullough <[email protected]> wrote:

>
> Folks,
>
> I have had a disk go bad on me, causing me to lose one PV.
>
>
> I seem to have retrieved the partition using ddrescue, but it also seems
> to be missing some label information, because pvscan doesn't see it.
>
> Using hexdump, I see the string " LVM2 " at 0x1004, but nothing before
> that.  The whole phrase is:
>
> 0x01000  16 d6 8e db 20 4c 56 4d  32 20 78 5b 35 41 25 72
>
>
> I find what appears to be an LVM2 configuration section at 0x1200, and
> so I was able to read the UUID that this PV should have.
>
>
> On another machine, I dumped a PV partition, and find "LABLEONE" at
> 0x200, with the same " LVM2 " at 0x01000.
>
> I was concerned that my dump was offset, but the comparison to the
> "good" one suggests that that isn't the problem, but just the missing
> "LABLEONE" and related information at 0x0200.
>
> If I do a "pvcreate --uuid xxxx" would this fix that recovered partition
> so that pvscan and friends can work properly, and I can finally boot
> that machine?
>
>
> Thank you,
> Brian
>
>
> _______________________________________________
> linux-lvm mailing list
> [email protected]
> https://listman.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>
>

_______________________________________________
linux-lvm mailing list
[email protected]
https://listman.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.