We are in the process of migrating our disk from one SAN to another. We are in the enviable position of having both SANs available to our Microsoft SQL Server 2008 R2 SP1 cluster at the same time. Our SQL Server instance is not virtualized.
I began working on a process to migrate all our databases with as little downtime as possible. I imposed the “as little downtime as possible” requirement on myself to see if it was possible to migrate this data with no downtime whatsoever. I time-boxed my efforts to about 3 days of intermittent work (when I could steal the time). Technically, our customers would be fine with a little bit of downtime outside of business hours, but I wanted to challenge myself and see what I could come up with.