Re: Group foo not uidvalid?

[Jeff Senn <senn@maya.com>]

Ed L. Cashin <ecashin@coe.uga.edu> writes:

> Kai Großjohann <Kai.Grossjohann@CS.Uni-Dortmund.DE> writes:
> 
> > Somehow, I mis-created a group and now get the above message every
> > time the group is written to (changed, includes expiry for instance).
> > Except for the message, things appear to work okay.
> > 
> > What might I have done (wrong)?  
> um...

Wasn't there some problem with certain servers changing their UID
to aggressively when the group was made empty...

> > How do I make the group uidvalid?
> 
> This works most of the time: from group buffer edit group parameters
> with "G p" and remove (uid-validity xxxxx) from the list.  Hit "C-c
> C-c" and the messages go away.  Sad, but effective.
> 
> > What does uidvalidity _mean_?
> ...um...

Basically whether some 'group named X' is still the _same_ 'group
named X' that your client probably cached information about the last
time you were connected. (e.g. suppose you delete and re-create a
folder by the same name in a different client) The server creates a
number (UID) that can be used to compare for identity for a group
across sessions -- theoretically this number is never reused.

[This is similar to generation number schemes used in low-level
network files systems to prevent aliasing in the case reuse of
primary identifiers like inodes...in case that helps :-) ]

-- 
-Jas