So I have two hard drives. The actual drives have been encrypted with TrueCrypt, and then the virtual encrypted devices have been combined into a volume group using LVM. Now TrueCrypt does not automatically mount my drives on startup (because it needs my password), so what happens if my server needs to be restarted? Should I just be able to mount the TrueCrypt volumes from command line and LVM will go on its happy way, or will I lose all my data because LVM will think all my drives have disappeared.
If that is the case you can try the vgimport command to search for volume groups on your drives.
LVM data is actually stored on disk (In the encrypted TrueCrypt volume in this case), you might need to execute some commands that make the server pick-up the LVM again after mounting the TrueCrypt disks, but I'm not 100% sure about that.
So I found out the answer to this a while ago but forgot to update here. To re-recognize LVM devices if they do not exist on startup, run the following commands:
- Scan for devices:
- Re-activate Volume Group:
vgchange -a y
- Re-activate Logical:
lvchange -a y <your VG here>
Then everything should be good.