How to mount LVM Volume?

Question

I'm trying to mount an LVM2 volume, but all the instructions I see online say to mount the Volume Group, such as 'mkdir -p /mnt/VolGroup00/LogVol00' but I don't know how to figure out the name of it. I see the drive in Palimpsest, and that's all the info I know. How do I do this?

Answer 1

Faced this problem a while ago, I'd posted this on my blog

List out all your partitions, type

linux:/ # lvmdiskscan

You will get a list of something like this

File descriptor 3 left open
File descriptor 4 left open
/dev/dm-0 [ 9.67 GB]
/dev/sda1 [ 78.41 MB]
/dev/dm-1 [ 6.44 GB]
/dev/sda2 [ 115.52 GB]
/dev/dm-2 [ 2.00 GB]
/dev/sda3 [ 18.11 GB] LVM physical volume
/dev/sda5 [ 15.33 GB]

Make a note of /dev/dm-x, those are the devices which correspond to the LVM partitions. Also do note the sizes.

Next, type lvdisplay to show a detailed list of all logical volumes available.

lvdisplay |more

LV Name /dev/system/home
VG Name system
LV UUID 1QP9XM-vlKi-umNO-CXvV-TnZN-RCLk-e1FDIr
LV Write Access read/write
LV Status available
# open 1
LV Size 9.67 GB
Current LE 2475
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0

— Logical volume —
LV Name /dev/system/root
VG Name system
LV UUID D1fKUJ-uU1C-jlVB-4imh-rrgy-FQu0-TC2Ssm
LV Write Access read/write
LV Status available
# open 1

LV Size 6.44 GB
Current LE 1649
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1

— Logical volume —
LV Name /dev/system/swap
VG Name system
LV UUID w5LqIb-xvcr-Xsbk-y3wg-lT3i-LqdN-GFK8Mi
LV Write Access read/write
LV Status available
# open 0
LV Size 2.00 GB
Current LE 512
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:2

Now from the above set of data we can deduce that my /home partition, of size 9.67 GB is available as LV group /dev/system/home on /dev/dm-0

Now that we know where the partition is available, we can proceed with the mounting using the mount command, as

mount /dev/md-0 /home

And there you go, your LV partition is mounted!

Answer 2

You can get a list of volume names by running lvscan. The output will look like

/dev/VG1/LV1
/dev/VG1/LV2
/dev/VG2/LV3

i.e. with the volume group names in the middle and logical volumes at the end. See if any of them correspond to the information in Palimpset.

Also, compare to the list of disks already mounted (mount), and see which one isn't there. It might look a little different, e.g.:

$ mount
/dev/mapper/VG1-LV1 is mounted on /usr
/dev/mapper/VG1-LV2 is mounted on /home

You can see where the volume group and logical volume appear at the end.

Once you've found the right one, mount it in the usual way:

mount /dev/VG2/LV3 /mnt