Promise Technology FASTTRAK SX4300, SX8300 RAID 5 Block Striping with Distributed Parity

Models: SX8300 FASTTRAK SX4300

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FastTrak SX4300, SX8300 User Manual

RAID 5 – Block Striping with Distributed Parity

RAID level 5 organizes data across the disk drives of the logical drive, and distributes parity information across the disk drives along with the data blocks. This organization allows increased performance by accessing multiple disk drives simultaneously for each operation, as well as fault tolerance by providing parity data. In the event of a disk drive failure, data can be re-calculated by the RAID system based on the remaining data and the parity information.

The adjustable block size of the RAID 5 logical drive allows for performance tuning based on the typical I/O request sizes for your system. The block size must be set at the time the logical drive is created and cannot be adjusted dynamically.

RAID 5 makes efficient use of hard drives and is the most versatile RAID Level. It works well for file, database, application and web servers.

Distributed Parity

Data

Blocks

Disk Drives

Figure 3. RAID 5 Stripes all drives with data and parity information

The capacity of a RAID 5 logical drive is the smallest disk drive size multiplied by the number of disk drives, less one. Hence, a RAID 5 logical drive with four 100 GB disk drives will have a capacity of 300 GB. A logical drive with two 120 GB disk drives and one 100 GB disk drive will have a capacity of 200 GB.

RAID 5 logical drives on the FastTrak SX4300 consist of 3 or 4 disk drives.

RAID 5 logical drives on the FastTrak SX8300 consist of 3 to 8 disk drives.

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Promise Technology FASTTRAK SX4300, SX8300 user manual RAID 5 Block Striping with Distributed Parity