Originally posted by: ktwebb
RAIN is a stripe across servers disk resources. Similar to a RAID stripe, except across servers instead of disks in a single server.
How is it different from NLB? How is it similar is a better question. It isn't. MS NLB's are two identical machines that split the load between them. Round Robin if I remember correctly. Not really a load balance in the truest sense.
Microsoft Cluster service needs a shared resource between the cluster nodes. An SCSi or Fiber Nexsan AtaBoy for instance. There is no seperate shared resource in RAIN. The entire cluster is a shared resource as the data is scattered across the farm.
The only thing similar about RAIN and the other solutions you asked about is they offer some form of redundancy. How they implement it is completely different as is any form of performance enhancement. Personally I've never used a RAIN array. Sounds interesting though.