RAID 0, RAID 1, RAID 5, RAID 10

RAID stands for Redundant Array of Inexpensive (Independent) Disks.
On most situations you will be using one of the following four levels of RAIDs.

• RAID 0
• RAID 1
• RAID 5
• RAID 10 (also known as RAID 1+0)

This article explains the main difference between these raid levels along with an easy to understand diagram.

In all the diagrams mentioned below:

• A, B, C, D, E and F – represents blocks
• p1, p2, and p3 – represents parity

RAID LEVEL 0

Following are the key points to remember for RAID level 0.

• Minimum 2 disks.
• Excellent performance ( as blocks are striped ).
• No redundancy ( no mirror, no parity ).
• Don’t use this for any critical system.

RAID LEVEL 1

Following are the key points to remember for RAID level 1.

• Minimum 2 disks.
• Good performance ( no striping. no parity ).
• Excellent redundancy ( as blocks are mirrored ).

RAID LEVEL 5

Following are the key points to remember for RAID level 5.

• Minimum 3 disks.
• Good performance ( as blocks are striped ).
• Good redundancy ( distributed parity ).
• Best cost effective option providing both performance and redundancy. Use this for DB that is heavily read oriented. Write operations will be slow.

RAID LEVEL 10

Following are the key points to remember for RAID level 10.

• Minimum 4 disks.
• This is also called as “stripe of mirrors”
• Excellent redundancy ( as blocks are mirrored )
• Excellent performance ( as blocks are striped )
• If you can afford the dollar, this is the BEST option for any mission critical applications (especially databases).

Import A Foreign Disk

When you move a dynamic disk from one computer to another this dynamic disk is flagged in Disk Manager" as a foreign disk. In order to access this foreign disk you must import it first.

To Import The Foreign Disk

Start >> Control Panel >> Administrative Tools >> Computer Management >> Disk Management >> Right click on the foreign disk >> Select Import Foreign Disk.

What if the "Import Foreign Disk" is not available. This would happen if you are using different Windows version (eg. from Windows XP Professional to Home. Where Home has limited features).

Convert To Basic Disk

To make the disk accessible to the new machine you will need to convert it to a basic disk. However this process will destroy the data on the disk.

What To Do

In this is the case you will need to put the disk back into the original machine and then remove all the data or the most valuable data to another location such as

• CD/DVD
• external drive
• flash drive

then you can convert the dynamic disk to basic disk and copy back the data on it.