I have a SuSE 9.2 box that's locking up so much that I've decided it would be better to just reinstall instead of troubleshooting further. However it has a lot of non-OS data that I don't want to lose after the reinstall. This data is on LVM-managed volumes, some VGs span multiple PVs, etc. It sounds like the LVM stuff is stored in the PVs themselves, so I'm hoping that even if I wipe /, /etc, /usr and all the other system stuff I will still be able to mount the LVMs after reinstall. However I'm a little paranoid with 200GB of data at stake. Is this safe to do?

Yes, it is safe.

Unless you direct the installer to modify the LVM or unless you modify one of the LVM physical volumes, your stuff in the logical volumes will not be modified by the reinstallation.

And yes, the LVM is self contained and its existence is not dependent on the OS being present. The same is true for Raids set up with mdadm.

That's great, thank you.

Of course, it’s always a good idea to backup the critical stuff, before you do something on a drive that might be “dangerous”.

Certainly. What I may do is move the drive with all the LVs (luckily they are all on one drive) to another box before I do the reinstall. This will protect the data from me doing something stupid during the reinstall, as well as allow me to access the data while I fiddle with the other machine.

Of course, if I had just moved the drive in the first place it would have proved to me that the LVM info is in the PVs themselves and obviated the need for this entire thread. Oh well.

I like the idea about disconnecting the drive.

Just as a point about disconnecting the drive, I use large USB 2.0 drives to do static backups. In each case, most of the drive is formatted as an LVM2, with small NTFS and FAT32 partitions at the end. The drives move around and get plugged into different systems and they all read the LVM without any problems.

Now you understand why I am absolutely sure that the LVM is self contained.