Thanks everyone for the feedback. Bob asked for more information about what is going on with my system. I have some dead or detached disks; since they
might come back I don't want to eliminate them from LVM's knowledge yet.
Here's the fuller story. It seems simplest to explain chronologically.
In the beginning was a system with a mix of IDE and SATA disks. Some of these had been in other systems before, and there were 2 separate LVM volume groups. The computer and the primary (SATA) disk died.
I had another, diskless, PC, to which I attached a new drive (call it fred) and installed a new system. That was Debian wheezy just before release. I attached some of the other drives through a drive case and fiddled with recovery.
Then I got a new, regular PC, which came with a SSD on sda that had Ubuntu preinstalled. I moved most of the non-damaged disks to the new system. It has limited IDE and so I only attached one of those. fred is my primary boot disk on the new machine. Since then, the IDE drive seems to have died, but it may be just a cabling issue.
Someone suggested I might be able to recover the original dead SATA drive by putting it in the freezer.
So all of the disks that are detached might come back, either because I fix the failure or attach the IDE. Thus I do not want to removed them from LVM just yet. On the other hand, I have backups, and so I am reconstructing using them rather than monkeying around with the absent drives.
The one other oddity is that one of the GPT tables has gotten a little funky
Using /dev/sde
(parted) p
Error: The backup GPT table is corrupt, but the primary appears OK, so that will be used.
OK/Cancel? OK
Warning: Not all of the space available to /dev/sde appears to be used, you can fix the GPT to use all of the space (an extra 4 blocks) or continue with the
current setting?
Fix/Ignore? I
Model: WDC WD20 EARS-00MVWB0 (scsi)
Disk /dev/sde: 2000GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number Start End Size File system Name Flags
1 20.5kB 1000MB 1000MB 1
2 1000MB 2000GB 1999GB 2
I'm not sure what's going on; I definitely did some manipulations on the GPT table, but since they were all with standard tools I don't know why it would be corrupt. Again, I've been deferring any action, including the suggested repair, to focus on other things.