Thanks Jan,

On Sun, Nov 05, 2006 at 11:43:09AM -0500, Jan Harkes wrote:
> However there are a couple of places where we implicitly add .suffix,
> for instance for clones and backup volumes.

To eliminate the risk of collisions the suffix might be moved to the beginning
as well, like "0backup/foo".
As all "path-like" volume names begin with a slash, that would be safe.

On the other side, a rule like the above implies a "prohibition"
of digits 0 to 7 as the first character of a non-replicated volume name.
My point of view is though that path-like /names are "natural" and the rest
is special cases anyway :)

> Now if the client had a way to get the list of clone and backup volumes
> they could be shown when we expand an object alongside the replicas,
> something like,
> 
>     $ cfs expand foo
>     $ ls -l foo
>     -rw-r--r-- 1 7768 nogroup 41 2005-08-02 12:02 marais.coda.cs.cmu.edu
>     -rw-r--r-- 1 7768 nogroup 41 2005-08-02 12:02 marais.coda.cs.cmu.edu.backup
>     -rw-r--r-- 1 7768 nogroup 41 2005-08-02 12:02 mozart.coda.cs.cmu.edu
>     -rw-r--r-- 1 7768 nogroup 41 2005-08-02 12:02 mozart.coda.cs.cmu.edu.backup
>     -rw-r--r-- 1 7768 nogroup 41 2005-08-02 12:02 verdi.coda.cs.cmu.edu
>     -rw-r--r-- 1 7768 nogroup 41 2005-08-02 12:02 verdi.coda.cs.cmu.edu.backup
> 
> Or possibly append the date+time when the backup or clone volume was
> created (@20061105001511). This way we never need to rely on the name in
> the volume database to access backup volumes because expand mounts them
> based on the volume-id, it just needs a way to discover what those id's are.

That looks good (never have to mount a replica), but I can imagine a situation
when a user needs to access a backup volume, while at the same time some script
of her is running and expects unexpanded paths to her files.

To work around, it might be necessary to be able to mount a volume
at another place, and expand it there, or do other doubtful (?) things.

Anyway, I'm making a change "foo.N" to "Nfoo"
in a new realm and see if I notice any problems.
Should be fine until I need mount points named something.backup :)

A quick test with the change (in createvol_rep only) shows
that I can create, access and purge such volumes. Great. Thanks!

Rune