By André on
Saturday, October 20, 2012 11:05 AM
Disk input/output (I/O) performance is the single biggest constraint on database performance in the SharePoint world.
Running SharePoint on an underpowered or poorly designed SQL Server environment will slow performance throughout the farm.
Because it's equally important to make sure SQL Server databases are kept highly available, some level of disk redundancy is usually factored into physical designs for database servers. Disk redundancy is often classified by RAID levels.