[OpenAFS] Re: All limitations of OpenAFS

Andrew Deason adeason@sinenomine.net
Tue, 26 Jan 2010 11:16:14 -0600

On Tue, 26 Jan 2010 13:49:27 +0100
Lars Schimmer <l.schimmer@cgv.tugraz.at> wrote:

> Some limitations were open:
> - -max number of volumes per cell/fileserver?

Somewhere around 2^31, I think. The vol id namespace should give you
2^32, but you usually start somewhere in the middle (probably alterable
with deliberate intervention at cell creation). I'm not sure what
happens if you try to wrap around the vol id counter.

And that's actual volumes, not number of volume groups; usually for each
RW volume you take up 3 ids to preallocate the RO and BK vols (but you
could alter vos not to do that).

> - -max number of ACL entries in a directory?

20. Includes both positive and negative ACL entries, if I recall

> - -max numbers of "supergroup feature" includes?

Do you mean how far you can nest groups? I don't know if there is a
limit on that.

> - -max number of db servers in one cell?

As has been said, you hit practical limits at about 5; I don't remember
the actual max, but beyond that you don't usually get much benefit.

Andrew Deason