For a heavily used volume, you can improve disk response time by distributing volume segments across two or more disks. For background information, see Understanding Volume Segments.

If one of the disks fails, the entire volume becomes unavailable. Therefore, you should mirror or duplex drives containing spanned volumes. (See Mirroring and Duplexing for concepts and Mirroring and Duplexing Partitions for instructions.)

If a disk containing a spanned volume fails, the entire volume must be restored from a backup across all segments before you can use it again.

The most effective way to distribute volume segments is to do so equally across the disks. Do not simply fill up a disk, add another, add another, etc.