User manual

Fast Trak TX2200 / TX4200 User Manual
48
Logical Disk Terms
Logical disk
A logical disk (array) is formed from a group of two or more disk drives that
appear to the PC’s operating system as a single drive. The FastTrak Serial ATA
RAID Controller provides the organization and management for your disk drives
so they can work together in this way. FastTrak allows you to create a single-
drive RAID 0 logical disk but such a logical disk has no advantage over any other
single disk drive.
Member
The individual disk drives in a logical disk are called members. Each member of a
specific logical disk has coded in its reserve sector the configuration information
that identifies the drive as a member of a specific logical disk. All disk members in
a logical disk are recognized as a single physical drive to the PC’s operating
system.
Types
FastTrak logical disks conform to the Redundant Array of Independent Disks
technology, or RAID. RAIDs are used to:
• Increase throughput performance
• Provide fault tolerance protection
RAID 0 Stripe increases performance by working multiple disk drives in parallel or
simultaneously. RAID 1 Mirror provides fault tolerance by providing a full copy of
the data on two separate disk drives. RAID 10 Mirror/Stripe (TX4200 only)
combines RAID 0 and RAID 1 techniques to provide both increased performance
and fault tolerance.
The chart below summarizes the features and advantages of each RAID level
that you can achieve with the FastTrak Controller card.
RAID Level Performance
Fault
Tolerance
Capacity
No. of
Drives
RAID 0
Stripe
Highest No No. Drives x
Smallest Size
1 to 4
RAID 1
Mirror
Normal Yes Smallest Size
Drive
2 only
RAID 10
Mirror/Stripe
High Yes 2X Smallest
Size Drive
4 only