It's for this very reason that I won't use LVM anymore. It's just too darn much trouble to rescue anything from it.
There's a recent thread over at the fedora-list. Here's something that might help.
Jim Cornette wrote:
I searched the archives for whatever I had to do in order to get the
lvm activated. Here is one posting that I made:
https://www.redhat.com/archives/fedo.../msg01943.html
From an earlier posting someone suggested to run the following commands
to activate and later deactivate LVM volumes in rescue mode. I used
these commands on an external USB drive to get at data from a previous
installation and it worked. You might be able to get at your data in
this way.
Jim
Excerpt from earlier help.
Once booted into text-mode rescue, invoke the following commands:
lvm lvscan
lvm vgchange -ay
This will scan for all LVM volumes and then will make them active and
accessible.
lvm vgchange -an
will deactivate them all.
end Excerpt:
Basically, the LVM volumes on the hard drive from an earlier install was
labeled / for the main partition and this label being the same as my
non-lvm clean install was also labeled /. When the kernel booted and the
saw the same label, it ignored the LVM which contained the / and swap
lvm content.
To access the partition, I ran the lvscan and vgchange commands. I then
had to make a mountpoint under /mnt to mount the LVM partition.
I believe I got the information as /dev-mapper/volgroup00/<whatever> ---
Sorry, I forgot what it is called, I no longer use LVM.
I took that information of where the volume was and used mount
/dev-mapper/volgroup00/<whatever> /mnt/olddrive and was able to access
all the content from the LVM after mounting it. I transferred all of my
desired information from the drive and never used it since.
There might be discussions in march of this year or close to that time
frame in the archives. The helpful person has not posted recently to my
knowledge but knew a lot about dealing with LVMs.
All of your swap partitions and other filesystem dvisions are all
contained in the LVM. The only partitions you should have are the one
for windows, the /boot partition and the third partition should be where
all of the LVM "partitions" or slices are kept. If you ran fdisk on the
/dev/sdb device, you should have three partitions. Without dev-mapper,
it does not show.
Good luck! It is possible, I just cannot remember the exact method that
I used to get at the LVM.
Jim