Managing RAID on Linux

Motherboard and System Compatibility

The most important issue to consider when purchasing a RAID controller is its interoperability with the rest of your system. Many controllers are designed specifically to work in server motherboards or with specific motherboard chipsets. Some controllers are even incompatible with certain hard disks and drive firmware. I cannot stress enough the importance of doing your own research before purchasing. When possible, avoid getting technical information of any kind from sales representatives. Instead, check the support section of the vendor’s web site for known issues, mine the archives of related discussion lists, and in general, search the Web for user reports about the controller. The Storage Review web site (http://www.storagereview.com) is a good place to look for third-party evaluations.

During my evaluation of hardware RAID controllers, I encountered compatibility issues with nearly every card I tested. I used several different motherboards (each with a different BIOS and chipset) and found that each card had problems with at least one of the motherboards, ranging from data corruption to general system failure. In some, but not all cases, upgrading the controller and the motherboard to the most up-to-date firmware resolved the issues. Ironically, the one card that worked with all three motherboards I tested did not work reliably with the disks I was using until I upgraded both the controller and the drive firmware.