Difficult areas for this exam will depend on the candidate’s background. Database administrators that work in an enterprise setting with storage administrators, as well as system administrators that handle the dirty hardware tuning details, will need to brush up on hardware design. The exam will strip away many of the layers enterprise database administrators take for granted. When you sit for the exam, forget about the huge enterprise SANs with gigabytes of cache. You will need to get back to the basics of RAID configuration. Remember, RAID 5 involves high write overhead because additional parity data that is written to the array. Generally, RAID 1 write performance is superior to RAID 5. In a database configuration, consider the needs of the volume. Log volumes are almost exclusively used for writing, so RAID 1 is the better choice for logs. RAID 5 generally has faster read times than RAID 1. When cost is a consideration, RAID 5 is more the more cost effective choice. RAID 10 is the most expensive solution, but offers the highest level of performance and convenience.