Will the new Xsan client included in Lion and Lion Server be backwards compatible with Xsan 2.1.1? Is Xsan 2.2 backwards compatible with Xsan 2.1.1? The reason I ask is that I have Xsan 2.1.1 running on two old G5 servers, and I am concerned about the path to moving onto an Intel server in the future. If the new Lion client/controller built into Lion is made to be backwards compatible, it will be a simple matter for me to connect a new Thunderbolt enabled Mini Server (when they become available <crosses fingers>) and have the new server take over as the primary Xsan controller. Add another Mini Server, and I can take the two G5's offline finally.
Otherwise, I will have to get a large Thunderbolt RAID, copy all my data to that RAID (a 3+ day prospect), tear down the existing Xsan, recreate it with a new server and then copy the data back again (another 3+ day prospect). This is not an acceptable upgrade strategy, and I hope very much Apple takes this into account this time. The last upgrade from Xsan1 to Xsan2 was fraught with peril, and I navigated those waters only after carefully digesting everything I could on the matter.
