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I just installed Manjaro on to a externalized usb hard drive. After I was done, I tried to boot from my previously working Mint distro (no full-disk luks) on my internal hard drive. The lvm volume groups had disappeared!?

 [crow ~]$ sudo lvm vgscan [sudo] password for crow: Reading all physical volumes. This may take a while... Found volume group "ManjaroVG" using metadata type lvm2 [crow ~]$ sudo pvscan PV /dev/mapper/cryptManjaro VG ManjaroVG lvm2 [465.51 GiB / 0 free] Total: 1 [465.51 GiB] / in use: 1 [465.51 GiB] / in no VG: 0 [0 ] [crow ~]$ sudo fdisk -l /dev/sdb Disk /dev/sdb: 465.8 GiB, 500107862016 bytes, 976773168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x00079473 Device Boot Start End Sectors Size Id Type /dev/sdb1 * 2048 499711 497664 243M 83 Linux /dev/sdb2 501758 976771071 976269314 465.5G 5 Extended /dev/sdb5 501760 976771071 976269312 465.5G 8e Linux LVM [crow ~]$ sudo pvs [sudo] password for crow: PV VG Fmt Attr PSize PFree /dev/mapper/cryptManjaro ManjaroVG lvm2 a-- 465.51g 0 [crow ~]$ sudo pvdisplay --- Physical volume --- PV Name /dev/mapper/cryptManjaro VG Name ManjaroVG PV Size 465.51 GiB / not usable 2.00 MiB Allocatable yes (but full) PE Size 4.00 MiB Total PE 119170 Free PE 0 Allocated PE 119170 PV UUID B8f73k-Najv-6hVM-XxHm-Wk9F-zeZ9-69MsxN [crow ~]$ sudo pvdisplay /dev/sdb5 Failed to find physical volume "/dev/sdb5" [crow ~]$ sudo file -s /dev/sdb5 /dev/sdb5: data

I have switched the disks around and now the non-working disk is /dev/sdb. I have read that there is meta data backup in /etc/lvm which is of course inside /dev/sdb5 and not /boot at /dev/sdb1. I would like to see a better answer for this.

If there is not a way to restore the disks then what are my options? Are these among them?

  • Are there any forensics tools that can give access to the data?
  • Another thing is the partition scheme was the standard linux Mint. If I reinstalled Mint could the new meta-data be used to try to recover the old?
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  • What do you get from sudo pvs and pvdisplay /dev/sdb5? Commented Sep 9, 2014 at 17:01
  • You missed the argument to pvdisplay. sudo pvdisplay /dev/sdb5. I presume /dev/sdb is where the Mint install you're trying to recover lives? If not, which disk does it live on? Commented Sep 9, 2014 at 17:29
  • Yes, it should be on /dev/sd5. command finds nothing. Commented Sep 9, 2014 at 17:38
  • Maybe they set up some LVM filter... Does grep -P '^\s*filter' /etc/lvm/lvm.conf give anything? Commented Sep 9, 2014 at 17:48
  • the readable /etc/lvm is now Manjaro aka Archlinux on /dev/sda, so I dont see what the use is. But anyways grep does not find anything. Commented Sep 9, 2014 at 17:58

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It appears that the header did get cleared off your physical volumes. Thankfully, LVM stores a fairly large header, including multiple backups of the metadata, in plain text.

So you can find the plain-text metadata using, e.g., sudo strings /dev/sdb5 | less and use that metadata to restore the physical volume. Note that there will possibly be multiple copies from different dates; make sure to use the most-recent (there is a date stamp in them). Once you've used strings (and some hand-editing of its output, possibly) to get a config backup, you can use the steps in the CentOS LVM recovery documentation to restore access to the volume group.

I strongly recommend making an image of the partition before attempting recovery.

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  • I was able to recover the partition. Thx. One thing though: strings did not capture the closing } brackets. I used cat /dev/sdxx > data then used vim to find the correct file. Then I had to fsck the partition and hold down the y for a minute or two. But it worked. Commented Sep 9, 2014 at 22:13
  • @user17130 odd about that fsck. Anyway, keep that image that you hopefully took around for a bit, just in case. Also may want to check what you used to recover vs. what's in /etc to be sure. Commented Sep 10, 2014 at 0:33
  • I don't understand how you did, what have you done after cat /dev/sdxx > data? What did you edit/remove from this data file? All parts that concern old config contents or You kept just the last config content version or all other data too? And also, you chose this file for the --restorefile options of the pvcreate command? And what about vgcfgrestore? Commented Jul 7, 2018 at 1:59
  • @temp_user_4_commenting maybe you should ask your own question, since cat isn't anywhere in my answer AFAIK. Commented Jul 7, 2018 at 4:01

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