Sunday, May 7, 2017

Mounting Logical Volume Management (LVM) Volumes

I have two hard drives from an old Linux machine. These hard drives were under one Logical Volume Management volume. On another Linux host, I found these tools were very useful to get the data out.

  • Scan LVM volumes

    sudo lvscan

  • Activate LVM volumes

    modprobe dm-mod
    vgchange -ay

  • List and remove mapped LVM devices

    dmsetup ls
    dmsetup remove <device>

    where an example of "device" can be VolGroup00-LogVol01


When you see an error message like the following when you try to mount a volume,

# mount /dev/VolGroup00/LogVol00 mnt/
  mount: /dev/mapper/VolGroup00-LogVol00 is write-protected, mounting read-only
  mount: /dev/mapper/VolGroup00-LogVol00: can't read superblock

One solution that has worked for me many times is to remove the mapped LVM devices using the command we discussed in the above. For instance,

# dmsetup remove VolGroup00-LogVol00

If you perform a lvscan, you will find that the volume is inactive,

# lvscan
  inactive          '/dev/VolGroup00/LogVol00' [459.53 GiB] inherit

To activate the volume, we can run the following

vgchange -ay

Now you shall see that the volume is active,

# lvscan
  ACTIVE            '/dev/VolGroup00/LogVol00' [459.53 GiB] inherit

We can now mount the volume,

# mount /dev/VolGroup00/LogVol00 mnt/

1 comment:

  1. Hey dude, i could possibly not thank you enough for the work that you post here. You have helped me out numerous times and i am sure other people also. Great work, keep it up.