I go on vacation for one week and they try to change the entire strategy on us, eh? When I first started hearing rumbles about the changes announced by the Microsoft SharePoint Product Group via their blog it sounded like the world was completely changed and that all previously known storage strategies can be thrown out the window in favor of using RBS and storing whatever you want in the Content DB!
Happily that is not at all what was being said. While the recommended limits have been revised by Microsoft to suggest that significantly more can be stored, the key word in the statement is CAN, not should.
Let’s examine a few telling things from the Product Group’s blog article:
For a SharePoint content database up to 4 TB you need to additionally plan for the following two requirements:
Requires disk sub-system performance of 0.25 IOPS per GB, 2 IOPS per GB is recommended for optimal performance.
Requires the customer to have plans for high availability, disaster recovery, future capacity, and performance testing.
And you need to review additional considerations in the TechNet Boundaries and Limits article.
What this part is suggesting to us is we can us a single mirrored set (RAID1) for a large content database and get what Microsoft is defining as “optimal performance” using a 15k RPM drive scenario (approximately 180 IOPS per drive). Great if you are looking to get some separation and you are doing sequential I/O, however when you separate the BLOBs out of the ContentDB you aren’t doing sequential I/O anymore.