What files do I need in order to recover my data from LVM?

Question

I have Fedora 11 installed on a machine where the harddrive is failing, each time I boot it up it reports several errors. My plan is to do a fresh install of Fedora 12 on a new (larger SATA) harddrive then copy any data that remains uncorrupted off the old drive by plugging it in to the IDE port. Are there any config files I need to get off the failing harddrive so that I can mount the volume set once I have the new system set up, or will it get recognised automatically?

Any other gotchas I should watch out for? For example, I assume I should create the volume set on my fresh install with a different name?

Answer 1

I am not sure how you rescan the drive in a new installation, check the lvm docs. If you move the volume group to another machine, it will be scanned at boot.

But the config is saved in metadata at the start of each PV as you add it, that's how you can move volume groups between machines and they can still be used.

Yes, use a different name for your new volume group :-)

Regards
K

Answer 2

I would suggest booting to a LiveCD that supports LVM (Most newer distros do out of the box, like ubuntu) then drop to the console and see what you can see. You might need to start or restart lvm '/etc/init.d/lvm restart'.

I've also ran into a number of odd issues where having any files in /etc/lvm have made it impossible for LVM to find your existing setup or create a new one. Removing /etc/lvm and running /etc/init.d/lvm restart has cleared up this situation for me.

As someone else stated the information for your LVM is stored on the devices themselves so you don't need to worry about saving anything in /etc/lvm or in the case of a LiveCD it really doesn't matter at all if you remove it.