RAID Levels

In General most of the Organization will follow RAID 0 , RAID 1,RAID5 & RAID10.

RAID10 also known as RAID 1 + RAID 0

RAID stands for Redundant Array of Inexpensive (Independent ) Disks.

RAID 0 (Speed) : Stripped Blocks , No Mirror & No Parity

1. To implement RAID0 we need minimum 2 disks .
2. Excellent performance because blocks are stripped.
3. No Redundancy hence no mirror , no parity.
4. Not recommended for any critical systems.

RAID 1 (Data Protection ) : Mirrored Blocks , No stripe and No Parity

1. To implement RAID1 we need minimum 2 disks .
2. Good performance because no stripping and no parity.
3. Excellent Redundancy because blocks are mirrored.

RAID 5 (Data Protection and Speed ): Stripped Blocks and Distributed Parity


1. To implement RAID5 we need minimum 3 disks . 2. Good Performance
3. Good Redundency
4. Recommended if the DB is heavily read oriented because write operations will be slow .
5. Best cost effective option because it is providing both good performance and redundancy.


RAID 10 : Mirrored Blocks and Stripped Blocks

1. To implement RAID5 we need minimum 4 disks .
2. Excellent Performance because blocks are stripped.
3. Excellent Redundancy because blocks are mirrored.
4. Highly recommended for any critical applications if you doesn't bother about cost.

Points to Remember :

If budget is not concern consider RAID10 for transaction log , data and index files.
If you have budget restrictions then use  RAID 5 for data and index files and RAID1 for transaction log files .