On Sat, May 06, 2017 at 12:05:57AM +0200, Martin Wilck wrote: > Introduce a "fake" UUID for these devices to make sure kpartx > deletes only devices it had created previously. Otherwise kpartx > might e.g. delete LVM LVs that are inside a device it is trying > to delete partitions for. It seems to be wiser to make sure the > user delete these manually before running "kpartx -d". > > With the fake UUID in place, we can re-introduce the UUID check > for non-DM device that was removed in the earlier patch > "kpartx: dm_remove_partmaps: support non-dm devices". > > This disables also deletion of partition mappings created > by earlier versions of kpartx. If kpartx has been updated after > partition mappings were created, the "-f" flag can be used > to force delting these partitions, too. Indeed - always supply a uuid for every dm device created. Add a standard prefix to the beginning of it, ideally "KPARTX-" to be consistent with other dm tools ("LVM-", "CRYPT-" etc.) if you're able to break compatibility, but "part" is still unique and adequate. (Stacked devices can end up with a stack of prefixes - only the leftmost one counts.) Alasdair -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel