From: Brian McCullough <firstname.lastname@example.org>
To: LVM general discussion and development <email@example.com>
Subject: Re: [linux-lvm] Recovering "broken" disk ( 17th )
Date: Wed, 20 Oct 2021 09:38:28 -0400 [thread overview]
Message-ID: <20211020133828.GE9096@bdmcc-us.com> (raw)
On Tue, Oct 19, 2021 at 05:06:37AM -0500, Roger Heflin wrote:
> I would edit the vgconfig you dd'ed with an editor and make sure it looks
> reasonable for what you think you had.
It turns out, comparing the information that I pulled off of the drive
with what I find in /etc/lvm/backup, that the first part of the vgconfig
information is missing. As I said in one of my messages, the
information that I retrieved from the disk starts at 0x1200. I don't
know whether that is correct or not. It does not appear to be a proper
"backup" file, which I think it should be.
I rebooted ( partially ) the machine and copied the vgconfig backup file
from that, but am somewhat concerned, because I don't seem to be able to
match the UUIDs. The one that I seem to see in the vgconfig data that I
pulled off of the drive vs what I got out of /etc/lvm/backup. Maybe I
am just mis-reading it. I will continue my research for a bit.
> When you do the pvcreate --uuid it won't use anything except the uuid info
> so the rest may not need to be exactly right, if you have to do a
> vgcfgrestore to get it to read the rest of the info will be used.
Oh, thank you. I did see that things got somewhat different on the
target drive when I did "pvcreate --uuid --restorefile." I got paranoid
when I saw that, and re-copied the ddrestore file back to the target
drive before I did anything else. Should I do "pvcreate --uuid
--norestorefile," instead? Then, once it is back in the machine, do the
pvscan and vgcfgrestore, and expect good things?
> I have seen some weird disk controller failures that appeared to zero out
> the first bit of the disk (enough to get the partition table, grub, and the
> pv header depending on where the first partition starts).
I APPEAR to have a partition table, containing an NTFS partition, an LVM
partiton ( the one that I am concentrating on ) and a Linux partion. I
would have thought that it was all LVM, but my memory could easily be
> You will need to reinstall grub if this was the bootable disk, since there
> were 384 bytes of grub in the sector with the partition table that you know
> are missing.
Fortunately, this is all data, nothing to do with the boot sequence,
except that the machine will not boot with the missing PV.
linux-lvm mailing list
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
next prev parent reply other threads:[~2021-10-20 13:39 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-18 2:17 [linux-lvm] Recovering "broken" disk ( 17th ) Brian McCullough
2021-10-18 14:49 ` Roger Heflin
2021-10-18 19:45 ` Brian McCullough
2021-10-19 10:06 ` Roger Heflin
2021-10-20 13:38 ` Brian McCullough [this message]
2021-10-20 18:01 ` Roger Heflin
2021-10-20 18:04 ` Roger Heflin
2021-10-21 6:13 ` Brian McCullough
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