Overland Storage REO 9000 setup guide Redundant Array of Independent Disks RAID

Setup Guide

						Management
						browser
						interface (console)
		LAN
Server 1	Server 2	Server 3	Server 4	Server 5	Server 6	Server 7	Server 8
			GbE or 10/100

	GbE or 10/100		GbE or 10/100
GbE or 10/100		GbE or 10/100	GbE or 10/100
	GbE or 10/100
	GbE or 10/100	GbE or 10/100
	Backup server		Backup server
10/100	SCSI		SCSI
Management
	Tape sub-system		Tape sub-system

REO

Redundant Array of Independent Disks (RAID)

RAID provides convenient, low-cost, reliable storage by saving data on more than one disk drive simultaneously. If one disk drive in a RAID 5 configuration becomes unavailable, the others continue to work in a degraded state, thus avoiding downtime for users.

Note: Because RAID 5 is designed for data protection, you might see performance degradation when compared to JBOD operations.

RAID allows you to group the individual disk drives on the REO Appliance into logical disk drives of different sizes. You can configure your REO Appliance to create two physical RAID volumes by selecting either of the following RAID options:

„RAID 0. This configuration uses striping, which provides enhanced performance and volume-level capacity. It divides the data into blocks and writes each block to a separate disk drive, which improves performance by dispersing the input and output load. RAID 0 does not provide data redundancy.

„RAID 5. This configuration uses striping and distributed parity, which provides a balance between performance and availability. In addition to dividing the data into blocks as described for RAID 0, the parity information is also striped across the disks. If one of the disk drives fails, you can use the parity information to rebuild the lost data.

In addition to using either of the preceding RAID configurations, you can also take advantage of logical volume management (LVM) and create logical volumes from the data pool.

Important Concepts to Understand W 15