Hello, We would like to use a shared filesystem. Will ALL the accounts on each server. Then we would use a load balancing package ( Resonate ) in front of the servers. Should one server fail the service would continue.
Network /\ / \ / \ / \ ResonateMaster-----ResonateSlave |\ /| | \ / | | \ / | | \ / | | \ / | | \/ | | /\ | | / \ | | / \ | | / \ | | / \ | |/ \| cyrusbox1 cyrusbox2 \ / \ / \ / \ / \ / \ / San ( shared filesystem) More cyrusboxes can be added to access the San and be linked back to the resonate boxes. This allows us to scale the service as necessary and provide redundancy in the event of a failure. If an imap server fails then the Resonate machines would not route ( bad choice of words perhaps but thats basically what Resonate does ) requests to it. So, each imap server must see the same filesystem and since one connection can come from one server to a mailbox and another from a different server some form of locking mechanism must be used to garuantee mutual exclusion. The big question as already asked is, Does a clustering file system that allows such file system sharing provide sufficient protection or would the application itself (in this case cyrus) need to be made aware that accesses to its data could be made by processes running on a different machine? We already do this with our web servers using AFS instead of a SAN. But the web servers deliver static data so doing this is very simple for them. No one's trying to write while the web servers are reading. Ken Murchison wrote: > > [EMAIL PROTECTED] wrote: > > > > Here is the idea: > > > > CyrusBox1 CyrusBox2 > > \ / > > `-------------\ __/ > > SAN > > > > The questions are: > > 1) Can it be done with out modifications to cyrus code? > > 2) if not, what has to be done > > 3) perhaps someone would like to do it for a reward in american presidents? > > What are you trying to accomplish with the SAN? Are your trying to have > a shared filesystem, or just shared storage (each server has its own > partition on the array)? > > If you're just looking for shared storage, than Cyrus _should_ work > as-is. > > If you're looking for a shared filesystem, then I think you want to look > below the application layer to something like SGI's CXFS (Clustered XFS > filesystem). > > Which president in particular? I'm partial to several Ben Franklins > myself ;-) > > Ken > -- > Kenneth Murchison Oceana Matrix Ltd. > Software Engineer 21 Princeton Place > 716-662-8973 x26 Orchard Park, NY 14127 > --PGP Public Key-- http://www.oceana.com/~ken/ksm.pgp