Data Storage Handbook

Learn all about RAID

RAID (or, redundant array of independent disks) is a way of storing the same data in different places on multiple disks. Placing data on multiple disks improves performance. Storing data redundantly also increases fault tolerance -- in the event that a disk fails, another disk can immediately take its place with no loss of service.

This handbook offers three related RAID tips. The first offers insight into RAID today, the second defines and details the most common RAID levels currently in use, and the final piece offers advice on how to choose the appropriate RAID level for your needs.

RAID: It's alive

RAID is still relevant today, possibly even more than in the past. However, it has become a transparent, standard feature that isn't often discussed. This segment outlines the state of RAID today.

RAID levels defined

This segment offers a listing of the RAID levels in use today and details the characteristics and applications of each.

How to choose the right RAID level

This segment offers nine things to consider when deciding which RAID level is right for your organization's needs.

Related RAID information:

Storage basics: RAID striping in detail

External SATA RAID vs. system replacement

Is RAID passé?

RAID 5 configuration

RAID configuration with three hard drives

RAID technology adds reliability and overcomes concerns

About the author: Greg Schulz is founder and senior analyst with the IT infrastructure analyst and consulting firm StorageIO Group. Greg is also the author and illustrator of Resilient Storage Networks (Elsevier) and has contributed material to "Storage" magazine and other TechTarget venues.

This was first published in June 2007