@36261 So, what is different today? The capacity of today's disk drives is much higher, while their cost is far...
less. The processing power of today's RAID controllers is also much greater, so you can actually have RAID-6 parity calculations offloaded from the main processor, so there is no performance impact on the server or array as their might have been years ago. Still, there is a performance penalty for the additional parity and the cost of the additional drive to retain the second parity data -- along with the all the other overhead, such as the drive tray space, power and other support needed within the array itself.
When you're considering RAID-6, examine how it performs with different workloads (e.g. sequential vs. random), and determine how it is optimized for rebuilds.
Go back to the beginning of the Disk Hardware FAQ Guide.