[OpenAFS] newbie questions

Harald Barth haba@kth.se
Tue, 11 Nov 2008 18:47:14 +0100 (CET)

> ... and how to add a new partition, exactly that's my question. I've
> tried it with vos create..., but I think I miss something.

I think you miss one abstraction level. What you mount into the
/afs/x/y/z are volumes, not partitions. Some few volumes have "fixed"
names. Like root.cell. Most of them you can make up yourself.
home.tompos may be a nice volume name for your home volume? When you
create a volume you have to decide on what partition you put it (vos
create...) but you can move the volumes around later without the users
even noticing (vos move...). You probably think about partitions as
the things that are "mounted". No. The volumes are the things that
are mounted and the partitions are only providing the physical space.

> I searched the whole internet, but no luck, everywhere is full with
> 'set up openafs', but not with adding a new fileserver:)

I'm afraid this is a bit outdated:

The problem with this document is that the tasks are not in a very
good order from a "learning and understanding" type or perspective.

Are there better documents?
Should we distribute an mostly empty example cell? (could be done as dumps)

> >> 3. What happens, if the somehow one of partitions disappears (eg. hdd
> >> get wrong, like a node server),l what is the right protocoll in this
> >> case, is there more possibilities? Did I miss something is the docs?
> >>     
> >
> > If one partition went away, it is no more reachable. But if you setup
> > another FS or another partitions (and created ReadOnly copies of your
> > ReadWrtite volumes on that partitions) OpenAFS will use the still
> > available RO copies on the remaining partitions.
> >   
> I gues, it in the howto, how to do it.
> Right now I'm interesting in if the clients will be locked up, or only they miss the files?

If the data is not there or the fileserver does not answer within
timeout (normally 30 sec) the file system will report an I/O error.

> Great. If I understand well, all server replicate contains its 'meta' data too.

In OpenAFS, data and metadata are stored at the same place. There are Lustre-like
extensions called AFS-OSD proposed to OpenAFS, but those are not in standard OpenAFS.