When you boot from a Ubuntu Live CD, you do not get access to your LVM volumes. LVM is a storage arrangement which allows you to create a file system across multiple discs. For example If you have 2 500GB discs, You can make a file system 1TB in size… Be aware that without a RAID storage system, this will not be fault tolerant.
Once booted into the Ubuntu Live CD, Open a terminal session, and enter the following commands
ubuntu@ubuntu:~$ sudo su -
This will give you root access
ubuntu@ubuntu:~$ modprobe dm-mod
Installs the LVM modules into the kernel so you can see your Volumes
root@ubuntu:/dev# apt-get install lvm2
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
lvm2
0 upgraded, 1 newly installed, 0 to remove and 1 not upgraded.
Need to get 325kB of archives.
After this operation, 918kB of additional disk space will be used.
Get:1 http://archive.ubuntu.com hardy/main lvm2 2.02.26-1ubuntu9 [325kB]
Fetched 325kB in 0s (726kB/s)
Selecting previously deselected package lvm2.
(Reading database ... 98423 files and directories currently installed.)
Unpacking lvm2 (from .../lvm2_2.02.26-1ubuntu9_i386.deb) ...
Setting up lvm2 (2.02.26-1ubuntu9) ...
Backing up any LVM2 metadata that may exist...done.
update-initramfs is disabled since running on a live CD
root@ubuntu:/dev# lvs
LV VG Attr LSize Origin Snap% Move Log Copy%
san vol1 -wi--- 467.00G
root@ubuntu:/dev# lvchange -a y san
Volume group "san" not found
root@ubuntu:/dev# lvchange -a y vol1
The rest of this code activates the LVM Volume ( Mine is called VOL1 in this case). You now have access to your LVM volumes.