Exchange and the loss of single instance storage

Great post up on the Exchange Team blog about SIS. I have talked about this to many customers, and it's nice to have a link to refer people to for an explanation.

http://msexchangeteam.com/archive/2010/02/22/454051.aspx

In short, single instance storage was invented when disks were expensive and massive amounts of storage cost companies a lot more money. It worked great on that scale. As Exchange gained in popularity, and those users gained data, the disk planning for Exchange became more important, as the random I/O that SIS wrote took more time to read in than a sequential I/O. By moving to a sequential read/write model, they were able to vastly improve IOPS. So now, disk space is cheap and plentiful. Server level 2TB disks are here/coming soon, and I have a few customers with plans to do DAG's on 2TB SATA's.