[OpenAFS] collective wisdom about limits on volume sizes?

[Russ Allbery]

Jim Rowan <jmr@qualcomm.com> writes:

> In the old days, AFS admins made lots of very small volumes.  A few GB
> was considered large.  One of the limits I was aware of was being able  to
> get the volume successfully backed up, and another involved  successfully
> moving it between servers.
>
> I'm out of touch with what the state-of-the-art allows today....  anyone
> care to offer advice?
>
> How big can we make volumes and have everything still "just work"?

We routinely make 15GB volumes without giving it a second thought and I
know other sites go an order of magnitude larger than that.  The main
reason why we try not to create 50GB volumes isn't due to the AFS software
but rather that, with large volumes, balancing sizes between server
partitions gets more annoying.

It can take quite a while to move a really large volume, but it works
fine.

> What issues might we run into as we grow volume sizes?

It's mostly just management issues.  If you have to evacuate a server, you
can't spread the content across a lot of other servers with only a bit of
space left if the volumes are huge.  If you need to move volumes off a
partition because it's filling, it can be harder if all the volumes are
huge.  That's the sort of thing to watch out for.

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