First Sector Value for Hardware RAID

About 75% of RAID controllers use all disk sectors for storing data, starting at sector 0. For those controllers, the First Sector value is 0. However, some controllers reserve an area at the beginning of the disks to store configuration information. Their First Sector value is the size of this area. This value varies among manufacturers and, within the same manufacturer, among specific controller models. Some special values we have encountered are the following:

• 0 for the first disk and 10 for the remaining disks (e.g., HighPoint, Rocket 100)
• 1024 for all disks (e.g., 3Ware)