Toshiba Magnia 560S - Manual (Page 33)

RAID Overview
Introduction to RAID
15
Disk Spanning
Disk spanning allows multiple disk drives to function like one big drive. Spanning
overcomes lack of disk space and simplifies storage management by combining
existing resources or adding relatively inexpensive resources. For example, four 60 GB
disk drives can be combined to appear to the operating system as one single 240 GB
drive.
Spanning alone does not provide reliability or performance enhancements. Spanned
logical drives must have the same stripe size and must be contiguous. In the following
graphic, RAID 1 array is turned into a RAID 10 array.
Spanning for RAID 10, or RAID 50
Table 2.2 describes spanning for RAID 10, and RAID 50.
Table 2.2 Spanning for RAID 10, or RAID 50
Level Description
10 Configure RAID 10 by spanning two contiguous RAID 1 logical drives. The
RAID 1 logical drives must have the same stripe size.
50 Configure RAID 50 by spanning two contiguous RAID 5 logical drives. The
RAID 5 logical drives must have the same stripe size.
NOTE: Spanning two contiguous RAID 0 logical drives does not produce a
new RAID level or add fault tolerance. It does increase the size of the logical
volume and improves performance by doubling the number of spindles.