The procedures discussed in this chapter are for software-based spanned volumes. Hardware-based spanned volumes (JBODs) are rarely encountered and will be briefly discussed at the end of the chapter.

Disk Extent First and Last Sector

Successful recovery depends on knowing the first and last sectors of each disk extent. To explain this, we use a hypothetical example below.

Assume there is a software-based spanned volume consisting of two disks. The disks are of identical size of 1,000,000 sectors each. The disks form a spanned volume. The total size will be less than 2,000,000 sectors because the first track (sectors 0 to 62) is reserved for the Master Boot Record. On Windows® 2000 or later, the last 2,048 sectors (997,952 to 999,999) are also reserved for dynamic disk configuration.

In computer science, addresses are usually zero-based. A drive with 1,000,000 sectors contains sectors 0 to 999,999.

The spanned volume will contain 1995778 sectors as follows: