[OpenAFS] Questions about 'vos move' and replicated volumes

Russ Allbery rra@stanford.edu
Mon, 10 Oct 2011 21:03:42 -0700


Garance A Drosihn <drosih@rpi.edu> writes:

> I have a few questions about replicated volumes.

> In the utility script named 'mvto.pl', the script says:

>     # If the volume is replicated and the read/write is already
>     # on the right server, we won't actually move it.  Just make
>     # sure there's also a replica on the same partition if the
>     # volume is replicated.  Otherwise, move the read/write
>     # site and its corresponding replica if applicable.

> Is there some significant problem which might come up if someone
> wanted to move a RW volume plus the RO version from one partition
> on a file-server to a different partition on the same fileserver?
> Or is the script just assuming there isn't much to gain by moving
> the AFS volume in that situation?

The script just doesn't have the logic implemented to do it properly, plus
in order to do this you have to temporarily reduce the replication, which
always makes me nervous.  For example, if the volume only has one
replication site and you try to do this operation, you will temporarily
get an unreplicated volume.  The problem is that you can't have two
replicas of the same volume on the same server, even on different
partitions.

-- 
Russ Allbery (rra@stanford.edu)             <http://www.eyrie.org/~eagle/>