By: Kevin Arnold

Simple Definition Brief History RAID Levels Comparison Benefits, Disadvantages Cost Uses Conclusion Questions? Sources

Redundant Array of Independent Disks Combining Several HDD’s Into One Logical Drive To Increase Fault Tolerance and Increase Performance First Implementations of RAID Allowed Only The Largest Companies To Be Able To Afford And Maintain Them In The 90’s When Personal Computers Became Popular, The Size And Cost Inevitably Went Down

First Studied By Computer Scientists At UC Berkeley In 1987 They Implemented The Idea Of Connecting More Than One HDD To A Computer And Make It Appear As One Drive, Increasing The Performance Of Computing Came Up With RAID Levels 0-5

RAID 0 RAID 1 RAID 1E (Enhanced) RAID 5 RAID 5E RAID 5EE RAID 6 RAID 10

Advantages – Excellent Performance In Reading And Writing Disadvantage – No Fault Tolerance Advantages – 100% Data Redundancy Disadvantage – Only 50% Of Drive Storage Can Be Used

Advantage – 100% Data Protection (Using Parity) Disadvantage – Lower Performance than RAID 1E Advantage – 100% Data Redundancy, Up to 128 Physical Drives Disadvantage – Not Available on All Controllers

“Fast, cheap, good: choose two”

Things To Consider RAID 0 – Starting At $1,500 Most RAID Providers Have Companies Send In A Hard Drive For Evaluation And A More Accurate Pricing Quote Planning And Design Hardware – Hard Disks, Enclosures, Power Supplies, Power Protection Software Setup And Training – Training Of IS Professionals Maintenance

Business Servers – Most Professionals Agree That Every Business, Except For Very Small Businesses, Should Have Some Sort Of RAID Set Up Workstations – Video File Editing, Graphic Design, CAD/CAM (Usually Not RAID 10) Personal PC’s – Usually Not Required, But Some Gamers Prefer To Have RAID 0 For Performance Reasons

RAID 0 Should Be Used To Increase Performance. No Data Recovery Option RAID 5 Is Used By Medium Sized Business, Not The Most Expensive And Provides Recovery Using Parity RAID 10 Is Used By Most Big Businesses Because They Can Afford It, Uses Data Redundancy On A Large Scale