How to mount LVM from an external drive?

Question

linux

So, there is a server with Linux (Ubuntu 12.04), the disk is marked with LVM.
There is a second physical disk, it also has LVM
How to mount this second disk without losing data?
Various pvs/pvscan/lvscan/lvmdiskscan/vgimport and others do not see volumes on the second disk.
In fact, before reinstalling the OS, both physical disks were in the same volume group.

Answer 1

Use kpartx (kpartx -a /dev/...) then vgscan.
if the VG names match, then it's better to use some livecd, rename the VG on an external drive, and then mount it to the main system.

Answer 2

Mounting an external drive is no different from mounting an internal drive.
Physically connect the drive.
See if it's connected:
It must be in the list
Then

# vgscan --mknodes
# vgchange -ay

Then mount readonly if you are afraid of overwriting data
If the disks had the same group names , then you need to either
boot from an external disk,
or rename the group by uuid

# vgscan
Reading all physical volumes. This may take a while...
Found volume group "VolGroup00" using metadata type lvm2
Found volume group "VolGroup00" using metadata type lvm2

I don't know how to find out if LV belongs to PV, so I took
advantage of the difference in disk sizes.

# vgdisplay | grep -i 'name\|uuid'
  VG Name VolGroup00
  VG Size 148.94 GB
  PE Size 32.00 MB
  Total PE 4766
  Alloc PE / Size 4766 / 148.94 GB
  Free PE / Size 0 / 0
  VG UUID pkb1cy-1JSf-n3Px-UYRi-eImv-e1Eg-t12BgY
  VG Name VolGroup00
  VG Size 74.41 GB
  PE Size 32.00 MB
  Total PE 2381
  Alloc PE / Size 2381 / 74.41 GB
  Free PE / Size 0 / 0
  VG UUID SjBmkg-YvMz-B160-tEds-Vqrg-SFMS-mYNimL

And now rename the group by UUID

# pvscan
PV /dev/sda2 VG vg160 lvm2 [148.94 GB / 0 free] 
PV /dev/hda2 VG VolGroup00 lvm2 [74.41 GB / 0 free] 
Total: 2 [223.34 GB] / in use: 2 [223.34 GB] / in no VG: 0 [0 ]

# lvscan
inactive '/dev/vg160/LogVol00' [147.00 GB] inherit
inactive '/dev/vg160/LogVol01' [1.94 GB] inherit
ACTIVE '/dev/VolGroup00/LogVol00' [72.47 GB] inherit
ACTIVE '/dev/VolGroup00/LogVol01' [1.94 GB] inherit

# lvscan
ACTIVE '/dev/vg160/LogVol00' [147.00 GB] inherit
ACTIVE '/dev/vg160/LogVol01' [1.94 GB] inherit
ACTIVE '/dev/VolGroup00/LogVol00' [72.47 GB] inherit
ACTIVE '/dev/VolGroup00/LogVol01' [1.94 GB] inherit

# mount -t ext3 -o ro /dev/vg160/LogVol00 /mnt/yourmountpoint