Hi all, I’m playing around with LVMs to expand data storage and I’m looking at what would be required to transfer those drives to another device, all the steps I can find require exporting the volume group and then importing on the other device. But what would be the case if your boot drive were to fail, and you needed to move the drives without being able to export the volume group. Can you just do an import with a new device, or are there other steps required to do so?
Secondly, is there a benefit to creating an LVM volume with a btrfs filesystem vs just letting btrfs handle it?
I try keep my data drives and boot drives separate on my servers, I make sure I can rebuild the server relatively easily so no matter what happens I can get back up and running. In my research on LVMs I wasn’t seeing anything saying you could just move the drives to a new setup, that you had to export and import first. In the case of a suddenly dead boot drive, I wouldn’t be able to do that. I did see some steps for backing up an LVMs metadata and recovering from that, so I might be sure I do that at some point, but another user said that modern distros should be able to scan for LVMs without issue, which is not what I found in my quick test in my setup. So I’ll be checking that out in a more modern setup to double check.
From what I was reading, recovering from corrupted metadata is not something I want to do. I’d rather not use LVM if that’s what’s required if I can’t just move the drives to a new server, as nice as it would be to resize filesystems on a whim.
If personal anecdote is good for anything, I’ve been using LVM on top of software RAID on Linux for close to 20 years now without ever losing a volume. The last time I lost data was on ReiserFS 3. Like I said, LVM does not protect against drive failure itself. That’s why I use RAID underneath. I’ve got my OS disk to protect against failures like that. Also frequent and verified backups of my data files to make sure that is protected.
And yes, modern (still supported) distros can scan LVM PVs on boot without issue.
LVM Physical Volumes (PV) can be moved between Linux machines without issue (I’ve done that several times), it’s not like hardware RAID where you have to have the same controller on both machines. Nothing I’ve done has ever required LVM metatata export/import.