RAID Explained


Only the three levels of RAID most commonly used are described.

RAID-0 is the most common. Although some feel that RAID-0 is not true RAID because it is not fault-tolerant, it is nonetheless the most popular and widely used level. RAID-0 is simplicity at its best as it provides only an array of striped disks. It is perfect for use in situations where fault-tolerance is not an issue, (a failed disk will cause all information to be lost). Video editing or any application that needs high bandwidth with high capacity are perfectly suited for RAID-0. RAID-0 requires a minimum of two drives to operate.


RAID 0
Access Time: Very Good
Transfer Rate: Good
Redundancy: None
Cost Per Megabyte Penalty: None
Applications: Large disk requirements, high performance databases



RAID 1
Access Time: Very Good
Transfer Rate: Good
Redundancy: Yes
Cost Per Megabyte Penalty: 100%
Applications: Small disk capacities that require redundancy



RAID 5
Access Time: Very Good
Transfer Rate: Good
Redundancy: Yes
Cost Per Megabyte Penalty: Varies:- 5 drive set = 20%, 6 drive set = 17%, 10 drive set = 10%
Applications: Multiuser environments, database servers, file serving, web site hosting



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