Comment 3 for bug 591475

This is a race condition in the way pvmove relies on polldaemon to show the percentage complete.

Because it is a race condition causing the issue, its going to be extremely difficult to reproduce reliably, though I believe it may become more likely with volume groups that have a large amount of metadata and physical volumes associated, since it is more likely the steps will take longer.

The patch is just a workaround. The proper way to fix this bug is to use a signal that informs the polling daemon when the pvmove has been a success.