Re: [linux-lvm] Help restoring a corrupted PV partition ( 18th )
On Mon, Oct 18, 2021 at 11:40:39PM +0200, Zdenek Kabelac wrote: > Dne 18. 10. 21 v 20:08 Brian McCullough napsal(a): > > > >I have had a disk go bad on me, causing me to lose one PV. Thank you for the thoughts, Zdenek. No, it was a hardware failure. Bad blocs, unreadable sectors, etc. According to ddrescue, this partition was recovered without any problems, although, as I observe later, the first part of the partition is zero. > > > >If I am not providing sufficient, or the proper, information, feel free > >to ask for more. > > > > > >I seem to have retrieved the partition using ddrescue and put it on to > >a new drive, but it seems to be missing some label information, because > >pvscan doesn't recognize it as a PV partition. > > > >Using hexdump, I see the string " LVM2 " at 0x1004, but nothing before > >that. The whole 16 bytes is: > > > >0x01000 16 d6 8e db 20 4c 56 4d 32 20 78 5b 35 41 25 72 > > L V M 2 > > > > > > > >I find what appears to be an LVM2 vgconfig block starting at 0x01200, > >extracted that to a file and was able to read the UUID that this PV > >should have. It is one of about a dozen that make up this VG. > > > > > >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. > > > > > >How to fix? > > > >If I do a "pvcreate --uuid " would this fix that recovered partition > >so that pvscan and friends can work properly, and I can finally boot > >that machine? > > Hi > > It's quite important to be aware how the disk corruption happened. > Was this plain disk hw error - or some crash of raid setup ? > > Normally you could restore PV with this: > > pvcreate --uuid --restorefile file_with_vg_backup /dev/d > vgcfgrestore --restorefile file_with_vg_backup vgname > > > But if the content of device was scramble by some 'raid' bug - you might > have problem to retrieve any usable data afterward. > > > Regards > > Zdenek > ___ linux-lvm mailing list linux-lvm@redhat.com https://listman.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
Re: [linux-lvm] Help restoring a corrupted PV partition ( 18th )
Dne 18. 10. 21 v 20:08 Brian McCullough napsal(a): I have had a disk go bad on me, causing me to lose one PV. If I am not providing sufficient, or the proper, information, feel free to ask for more. I seem to have retrieved the partition using ddrescue and put it on to a new drive, but it seems to be missing some label information, because pvscan doesn't recognize it as a PV partition. Using hexdump, I see the string " LVM2 " at 0x1004, but nothing before that. The whole 16 bytes is: 0x01000 16 d6 8e db 20 4c 56 4d 32 20 78 5b 35 41 25 72 L V M 2 I find what appears to be an LVM2 vgconfig block starting at 0x01200, extracted that to a file and was able to read the UUID that this PV should have. It is one of about a dozen that make up this VG. 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. How to fix? If I do a "pvcreate --uuid " would this fix that recovered partition so that pvscan and friends can work properly, and I can finally boot that machine? Hi It's quite important to be aware how the disk corruption happened. Was this plain disk hw error - or some crash of raid setup ? Normally you could restore PV with this: pvcreate --uuid --restorefile file_with_vg_backup /dev/d vgcfgrestore --restorefile file_with_vg_backup vgname But if the content of device was scramble by some 'raid' bug - you might have problem to retrieve any usable data afterward. Regards Zdenek ___ linux-lvm mailing list linux-lvm@redhat.com https://listman.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
[linux-lvm] Help restoring a corrupted PV partition ( 18th )
I have had a disk go bad on me, causing me to lose one PV. If I am not providing sufficient, or the proper, information, feel free to ask for more. I seem to have retrieved the partition using ddrescue and put it on to a new drive, but it seems to be missing some label information, because pvscan doesn't recognize it as a PV partition. Using hexdump, I see the string " LVM2 " at 0x1004, but nothing before that. The whole 16 bytes is: 0x01000 16 d6 8e db 20 4c 56 4d 32 20 78 5b 35 41 25 72 L V M 2 I find what appears to be an LVM2 vgconfig block starting at 0x01200, extracted that to a file and was able to read the UUID that this PV should have. It is one of about a dozen that make up this VG. 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. How to fix? If I do a "pvcreate --uuid " 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 linux-lvm@redhat.com https://listman.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
