[OpenAFS] Feature wish: remove partition while fileserver keeps on running

Andy Cobaugh phalenor@gmail.com
Mon, 27 Feb 2012 11:34:05 -0500 (EST)

On 2012-02-27 at 17:00, Lars Schimmer ( l.schimmer@cgv.tugraz.at ) said:
> Hi!
> Maybe I missed a point or two, but I wish I could remove and unmount a 
> /vicepX partition while fileserver keeps on running.
> The last weeks I needed to redo our iSCSI storages and that implies a lot of 
> mount/unmount/redo partitions of our OpenAFS fileservers.
> Each time I need to add/remove a partition, the safe way was to stop the 
> OpenAFS fileserver, mount/umount the partition and restart the fileserver.
> As I do not want to be the night owl, I did it in usual work shift - which 
> did annoy our users as service was broken a few minutes.
> Is there any way to do this a better way?
> (IMHO DAFS is only for volumes, not partitions, or?)

That is correct.

However, DAFS can make the current methods of adding/removing /vicep's a 
bit less painful.

In the past, what I've typically done to remove paritions is completely 
evacuate them with vos remove/move etc, unmount the partition, then bos 
restart <host> dafs. Unmounting a partition while a fileserver might still 
be accessing it is risky, but if you're absolutely sure that there's 
nothing left on it, then this is more or less safe IMO. You could also bos 
shutdown / unmount / bos startup if you want to be paranoid.

Adding partitions is easier. Mount the new partition, then restart.

With DAFS, restart times are extremely fast, and I believe callback state 
is preserved across restarts, so your clients shouldn't notice the restart 
if everything is working correctly.