[PATCH] Move machine-id to /var

[Havoc Pennington]

Robert McQueen wrote:
> Unless we have a use case for reboot-persisting UUIDs, it would be
> easier for users (live CDs, package maintainers, thin clients, embedded
> systems, etc) if it was kept in /var/run which is more likely to be
> writable on such unusual systems.

Why do you say this? The FHS clearly says that /var/lib has to be 
writable ... if someone is making it not writable they are just on crack.

> Persisting it across reboots seems as
> useless to me as persisting the name of the session bus socket, which we
> obviously don't try and do either.

The usefulness would be if we document the machine id as "best-effort 
persistent across reboots" - we'd say it ideally is and while on some 
deployment models it may not be, apps can still consider it worthwhile 
to e.g. attach a a cache to the machine id and try to keep that cache 
around across a reboot.

I don't see the downside of persisting across reboots; it gives apps 
possible additional info about machine identity.

> Is it too late to change this?

A day after the patch is posted, no ;-)

Havoc