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

[Malahal Naineni]

Christophe Varoqui [christophe.varoqui at gmail.com] wrote:
>    >
>    > My thoughts on fixing this:
>    > 1. Technically nothing wrong. Live with it and make sure that device
>    >       mapper's uuid are meaningless for user and fix 'multipath -l' to
>    >       not print uuid's.
> 
>    I don't like this one : the uuid is the communication medium with storage
>    teams in big IT departement.
> 
>    > 2. Don't support user_friendly_names in initrd. Could be just documented
>    >       or an option to multipath is added to ignore that feature and that
>    >       option is used in initrd calls!
> 
>    I let distributors comment on this one, but I guess it will replace a
>    confusion (a naming file in initrd the sysadmin have to keep in sync) by
>    another (root kparm not consistent with what you see on a booted system).
>    I personnaly agree that user_friendly_names disabled in initrd would be a
>    safer confuser.
> 
>    > 3. We could rename the devices instead of reload -- really fixing this!
>    >
> 
>    This one seems safe.

Sorry for the delay. I actually found another easier way to fix it!
Looks like the bindings file in initramfs and the active root file
system may not be in *sync* but not *inconsistent*. The problem happens
because the initramfs is mounted read/write, and multipath modifies
bindings file in memory at initramfs time that may become *inconsistent*
with the bindings file in the active root file system. 

The patch in a next mail will add an option to 'multipath' to not update
the bindings file. It will treat it as read-only, so devices that don't
have an entry in the bindings file will get WWID based names.

Thanks, Malahal.