cluster installer prompts for VG overwrite when installing on a completely empty disk

[amb]

The cluster installer should work unattended, but instead it needs an installer to manually select "Yes". If this option (partman-lvm/confirm_nooverwrite) is set to true, however, installs blow up fatally with a "VG name already in use" error. See  LP:154086.

We might just want to have the cluster installer write a trash partition table out to disk first. We could possibly also punt LVM.

[jdreed]

This is an issue for the beta, I believe, because the prompt also happens when overwriting an existing cluster machine with the same VG structure. I believe we didn't see it from Jaunty->Lucid because changed the LVM structure? Cluster machines probably shouldn't use LVM anyway. Or I agree, the installer should possible scribble over the partition table after the DESTROYS DESTROYS DESTROYS warning.

[jdreed]

I _think_ this is fixed in Natty, in that partman-lvm/confirm_nooverwrite now works (or appears to). I'll note that I tried writing an empty partition table (using partman/early_command and sfdisk), but I still get the confirmation prompt, so I'm slightly confused about what actually causes this and what doesn't.

[jdreed]

This was committed in r25157

[jdreed]

This works. I'm not entirely clear why scribbling over the partition table doesn't also remove LVM info. (Where is LVM metadata physically stored on the drive?)

[amb]

LP #154086 now has an explanation and a hackish workaround for this. The problem is that the old PVs become visible when the "new" disk partitions are created with the same boundaries.