Coda File System

volume and replicas naming

From: <>
Date: Sun, 5 Nov 2006 15:24:38 +0100

I happened to face a slight problem.

On one side, volumes' and volume replicas' names are in the same
name space (where mount points are matched), so that we can
mount either a volume as a whole, or a replica, if we append a dot+digit.

That's fine but that places a limitation on volume naming, a volume
should not be named to look like a replica, otherwise that name will
possibly collide at some time.

That may seem to be an extremely small limitation,
never name a volume with dot+digit suffix and you are fine.

Now, I am consequently naming volumes after their mount points.
That is a very desirable approach, helping to keep your data
ordered even when you get thousands of volumes.

The small limitation noted above renders such consequent naming
impossible, as soon as you have directories
 something and something.digit
and need them to be mount points for different volumes.

I would suggest using a prefix instead of a suffix for replica names,
so that a mount point /coda/realm/foo could correspond to volume "/foo"
but the replicas would be instead "0/foo", "1/foo" and so on,
never being able to erroneously match a path.

Then the default mountpoints (without explicit volume names) would mount
the replicated volumes as they do now,
and the special case of replica mounts would be taken care of by explicit
volume names in the corresponding mountpoints.

I wonder how deeply the current naming convention is hardwired into Coda,
would it be sufficient to modify createvol_rep / purgevol_rep scripts
to introduce the change? (then I could do it for my realms myself).

Thanks for the great file system!
Received on 2006-11-05 09:38:39