[dm-devel] [BUG] multipath-tools: uuid has become meaningless

[Malahal Naineni]

Hannes Reinecke [hare at suse.de] wrote:
> Malahal Naineni wrote:
> > This is where I was heading. I did some investigation and found that we
> > really need to rename to wwid based names before we finally rename to
> > the intended name. So we may actually have two passes just to rename
> > (first to wwid based names and then to actual names).  Also the current
> > code doesn't do rename followed by reload even if it is needed. Someone
> > sets friendly name and some other defaults that need reload like path
> > grouping policy etc, we just rename! Probably a bug in itself.

> You sure? I would rather rely on device-mapper uuids here.

Hannes, I am not sure what you are referring to when you say, "You
sure?" Are you saying if I am sure about this bug? If so, you can see
yourself by swapping couple entries in the bindings file. As I said,
you will notice this bug only when you enable 'user_friendly_names' in
initrd in real life!

> So we can use the known naming scheme for the uuid to regenerate the
> wwid; with this we can identify/access the device and we should be able to
> make do with just one pass.

Say, you have "mpath0[uuid0]" and "mpath1[uuid1]" loaded currently.  How
can we rename mpath0 to mpath1 and vice-versa? It does require an
intermediate step of renaming to something else, right? 
 
Thanks, Malahal.