On Mon, 2008-11-24 at 12:07 +0100, Dirk Heinrichs wrote: > Am Montag, 24. November 2008 11:30:25 schrieb William Kenworthy: > > > By transient storage I mean that the data is duplicated across across > > physical storage spaces so that if a machine goes down, the data is > > still available. > > OK, thanks. > > > I thought Andrews FS did that, but didnt see when > > looking at it yesterday. > > Yes, (Open-)AFS indeed does this. However, this replication is read-only. > This > means you can read the data as long as at least one replica is available and > write the data as long as the original (the read-write) volume is available. > There are also some other things to keep in mind: > > * AFS' primary tool for access control are its access control lists (ACL), > but > those are not posix, but AFS ACLs and they apply at the directory (not file) > level. However, that's usually sufficient, because one can work with subdirs > and symbolic links to implement more restrictive access for some files in the > same directory. > > * ACLs can also contain host names. > > * If a volume is replicated, the client always prefers the read-only path > (read-write volumes are usually accessed via /afs/.mycell.mydomain, while > read-only volumes (if they exist) are accessed via /afs/mycell.mydomain). So > if you want to modify a file you must explicitely open it via the rw-path. > > * Replication doesn't happen automatically, needs an explicit command. > > * Support for backup volumes is also there (comes with its own backup system). > > * Can move volumes to different servers while online. > > * Data is cached on the client. > > * You'll need Kerberos 5. > > If you have further questions, feel free to ask. > > Bye... > > Dirk >
Discovered this: http://en.wikipedia.org/wiki/List_of_file_systems#Distributed_file_systems Thats going to keep me busy for awhile! BillK -- William Kenworthy <[EMAIL PROTECTED]> Home in Perth!
