After lamenting how SAN technology hasn't led us to the Holy Land of 80 percent utilization and reduced costs that vendors promised, Reichman posits a new storage architecture for the enterprise with application-based silos of clustered DAS.
I, and most vendors, would argue the reasons for poor utilization are much more human than technological. I've certainly gotten requests from DBAs for 4 TBs of space for an application that could need that much four years from now -- if it's widely adopted across multiple divisions that haven't even seen it yet. I know that wouldn't be any different if we didn't have a SAN.
His real point, and one I could agree with and even argue further, is that application developers have a better handle on their data than a block storage device ever could.
VMware snapshots solve many, if not all, of the problems that array-based snapshots do, and Exchange 2007's CCR and SCR replication features can easily provide DR capabilities for everyone's favorite email server. After all, if you use a block- or file-based replication system for a journaling database like Exchange, Oracle, or SQL server, you have to replicate both the database and transaction logs. Replicate transactions themselves, and you've not only reduced the amount of data 50 percent, you've also eliminated replication traffic events like database defragmentation.