two physical disks with same volume group names preventing access

Question

My 8 year old computer with fc22 died. I have a new computer now running fc25. I had routinely backed up my most important data, so not all is lost, but I would like to look at what I have on my old disk.

I have a usb enclosure and put my old disk in it. It generates /dev/sdb1 and /dev/sdb2 on plugging in. The /dev/sdb1 partition is immediately accessible and it held /boot. The /dev/sdb2 was broken into partitions logically. Unfortunately, the volume group name given was "fedora". That is the same name given to the disk running my fc25 system. Output from pvs is

  PV         VG     Fmt  Attr PSize   PFree

  /dev/sda3  fedora lvm2 a--  928.51g    0 

  /dev/sdb2  fedora lvm2 a--  465.27g 4.00m

It is the second volume group that I want to get at.

Output from vgdisplay shows both "fedora" volume groups:

The info from each group is relatively boring except the last line. For one volume I get:

  VG UUID               nMitQe-QmR1-tBP7-CTqm-VBR3-zUj5-UuTIml

and for the other I get:

  VG UUID               0Fuho1-nVos-nYkZ-HFih-hPSK-dilF-AIDaxI

Of course both volumes show the VG name as "fedora".

That difference in UUID is my ray of hope that I can get to the data on the volume in the enclosure. A direct

 # mount /dev/fedora/home /mountpoint

does not get what I want. It just gives me a second mount of my fc25 disk, and not the disk in the enclosure.

Does anyone know how to exploit the info I have given to give me access to the logical volumes in the second partition of the disk in the enclosure?

Answer 1

The vgrename utility is used to rename volume groups.

In your case, the command vgrename UUID-of-old-vg old_fedora_VG should do the trick.

See man vgrename for more information on the program and it's uses.