Comment 5 for bug 1469309

With this fix we stopped seeing the issue I reported, but are still seeing at least one of the issues Greg mentioned, so I dug into this a bit more to see what's happening in these different cases.

The prompt to use "--force" comes up when attempting to use 'vgreduce --removemissing cinder-volumes'.

To recreate this you error you need at least 2 devices. Create a volume group named 'cinder-volumes' on the devices, then create a big enough logical volume (or more than one) to use physical extents from both devices. Then use 'dd' to overwrite one of the devices. Then run 'vgreduce --removemissing cinder-volumes'. This will produce an error saying there are still partial LVs in VG cinder-volumes, since cinder-volumes extended across both devices and one is now missing. It doesn't want to remove the missing PV from cinder-volumes because there are partial LVs, so it's asking for confirmation.

We could hit this scenario if system with multiple storage devices has an existing PV on one of the devices configured for use by cinder, and that PV is part of a VG with other PVs now missing (overwritten and used for other things since the node was last used for cinder, or maybe was just a loopback device on filesystem that's gone now).

Using --force will cause vgreduce to remove the missing PV, and to remove any LVs that used it. The charm will function then. The ability to use '--force' could be added as an option to the charm.

I'll submit a patch with a new 'remove-missing-force' option as you suggest Corey.

Greg mentioned two other failures - I think those are both unique bugs and separate from this one. I filed them as bug 1476418 and bug 1476419.