Chaparral K5312/K7313, G5312/G7313 manual Comparing RAID Levels, Volume Sets

G- and K-Series User’s Guide

Volume Sets

A volume set is the ability to create a host-accessible LUN that maps to a single disk in the array, similar to JBOD. Volume sets are non-redundant and have a capacity slightly less than the physical disk they are created from. Volume sets are useful if you have a single disk available and you don’t want to use it as a spare.

Note: For more information on RAID levels, see The RAIDbook: A Source Book for RAID Technology, published by the RAID Advisory Board (St. Peter, Minnesota: February, 1996).

Comparing RAID Levels

Table A-1illustrates the differences between the different RAID levels:

Table A-1. Comparing RAID Levels

RAID	Min No.	Description		Strengths	Weaknesses
Level	of Drives
RAID 0	2	Data striping	Highest		No data
		without	performance		protection—one
		redundancy			drive fails, all data
					is lost
RAID 1	2	Disk mirroring	Very high:		High redundancy
			•	Performance	cost overhead—
			•	Data protection	because all data is
					duplicated, twice
			•	Minimal penalty
					the storage
				on write
					capacity is required
				performance
RAID 2	n/a	No practical use	Previously used for		No practical use—
			RAM error		same performance
			environments		can be achieved by
			correction (known		RAID 3 at lower
			as Hamming Code)		cost
			and in disk drives
			before the use of
			embedded error
			correction

A-4