There are several important features that have been developed over the last few years
to improve the capabilities of RAID-equipped systems. They are usually found on high-end
systems that use more expensive RAID controllers. In addition to a capable controller,
these features may also require other hardware in the system to be designed to support
them. For example, the system case or RAID enclosure must be designed to support drive
swapping for that feature to work.
In this section I take a look at caching (including write caching), hot drive spares
and drive swapping, three key features that improve performance and availability in RAID
arrays. Finally, I discuss the important issue of RAID array expansion, and how to plan
for the future of your RAID array.
Next: Caching