[OpenAFS] newbie questions

Felix Frank Felix.Frank@Desy.de
Thu, 13 Nov 2008 10:28:46 +0100 (CET)

> Well, OK, but I'm sure, AFS is not for me.
> There are a relatively small cluster, it's aroung ~10TB right now. It has 
> many type of directories, Some of them are static, they have only a few 
> changes, and also they are smalls one. And there are a Projects directory 
> with more directorries. These are the big ones and these can grow up to the 
> size 4-5-6 TB. Unfortunately I cannot split them to different partitions 
> (volumes) because I don't know, which part of it will grow up.

Can a directory grow from ~1TB to >2TB overnight? If not so, it would be
feasible to move its data to an additional volume (on another server/partition)
once it passed a given threshold (say 1TB). The new volume will be mounted in
place of the offending directory, so the data is accessed in exactly the
same way after the operation.

For additional convenience, there is a patch that adds the capability of
actually *splitting* a volume at a given directory (the one that has
grown too much e.g.). AFS can then move the new volume to an additional 
server or partition without downtime for your jobs.

> So AFS would be great, but at least it should handle bigger volumes than 2 
> TB.

If you give it a shot, you may find that AFS's great flexibity can make bigger
volumes unnecessary. There's yet more to say in its favor, so hopefully you
can try it out after all.