====== Ubuntu - Disk - Recover LVM disks ======

If for some reason a disk cannot be read, the following may help.

  * Plug the disks in and try reading them.

----

===== List devices that may be used as physical volumes =====

<code bash>
sudo lvmdiskscan
</code>

<WRAP info>
**lvmdiskscan** scans all SCSI, (E)IDE disks, multiple devices and a bunch of other block devices in the system looking for LVM PVs.
</WRAP>


returns

<code bash>
  /dev/loop0            [      89.12 MiB] 
  /dev/ubuntu-vg/root   [      <1.82 TiB] 
  /dev/loop1            [     <14.75 MiB] 
  /dev/sda1             [     512.00 MiB] 
  /dev/ubuntu-vg/swap_1 [     976.00 MiB] 
  /dev/loop2            [     408.69 MiB] 
  /dev/sda2             [      <1.82 TiB] LVM physical volume
  /dev/loop3            [    <323.86 MiB] 
  /dev/loop4            [      54.50 MiB] 
  /dev/loop5            [      89.10 MiB] 
  /dev/loop6            [    <140.67 MiB] 
  /dev/loop7            [    <156.04 MiB] 
  /dev/loop8            [      54.50 MiB] 
  /dev/loop9            [      42.80 MiB] 
  /dev/loop10           [      <4.20 MiB] 
  /dev/loop11           [    <156.68 MiB] 
  /dev/loop12           [    <323.72 MiB] 
  /dev/loop13           [      14.74 MiB] 
  /dev/loop14           [       3.64 MiB] 
  /dev/loop15           [    <140.67 MiB] 
  /dev/loop17           [     <44.18 MiB] 
  /dev/loop18           [       3.64 MiB] 
  /dev/loop20           [     396.69 MiB] 
  /dev/loop21           [      <4.20 MiB] 
  1 disk
  22 partitions
  0 LVM physical volume whole disks
  1 LVM physical volume
</code>

That last line shows that a LVM Physical Volume has been picked up.  Good.

----

===== List all logical volumes in all volume groups =====

Get a list of volume names:

<code bash>
sudo lvscan
</code>

returns:

<code bash>
  ACTIVE            '/dev/ubuntu-vg/root' [<1.82 TiB] inherit
  ACTIVE            '/dev/ubuntu-vg/swap_1' [976.00 MiB] inherit
</code>

----


===== Install LVM2 tools, if needed =====

This step may or may not be required.

<code bash>
sudo apt install lvm2 
</code>

----

===== Verify your LVM partition(s) is/are detected. =====

<code bash>
sudo pvscan
</code>

returns

<code bash>
  PV /dev/sda2   VG ubuntu-vg       lvm2 [<1.82 TiB / 0    free]
  Total: 1 [<1.82 TiB] / in use: 1 [<1.82 TiB] / in no VG: 0 [0   ]
</code>

----

===== Scan for LVM Volume Group(s) =====

<code bash>
sudo vgscan
</code>

returns:

<code bash>
  Reading volume groups from cache.
  Found volume group "ubuntu-vg" using metadata type lvm2
</code>

----

===== Activate LVM Volume Group(s) =====

<code bash>
sudo vgchange -ay
</code>

The params to vgchange are:

<WRAP info>
  a = activate
  y = yes.  It will not prompt you.
</WRAP>


----

===== Scan for available Logical Volumes =====

<code bash>
sudo lvscan
</code>

returns:

<code bash>
  ACTIVE            '/dev/ubuntu-vg/root' [<1.82 TiB] inherit
  ACTIVE            '/dev/ubuntu-vg/swap_1' [976.00 MiB] inherit
</code>

----

===== Mount the Logical Volume =====

This should allow you to access the data on the drive, by going to the MountPoint.

<code bash> 
sudo mount /dev/YourVolGroup00/YourLogVol00 /YourMountPoint
</code>

----