Installing A Scsi Raid Array

As a Network Administrator you may ask yourself,"Why should I use RAID?"
The answer depends on you and what you are trying to do. 
Before deciding:
*explore the pros and cons of using RAID
*weigh the costs against the benefits
*compare the costs to your budget and decide what your priorities are.

Because RAID consists of multiple hard drive disks, there are more advantages over a single hard drive disk such as:
* increased capacity
* improved performance
* fault tolerance
* improved reliability

The ease at which a RAID system can be set up to provide better performance, and the ability to continue non-stop when a hardware disk failure 
occurs is a pretty good reason to use RAID. Any desktop PC can be converted to a RAID system providing you supply it with RAID controller ,
either SCSI or IDE, and the appropriate number of hard disks.(A RAID-5 volume requires at least three disks to allow for parity information).
You can create a RAID volume using either hardware-based or software-based solutions. Hardware-based RAID offers better performance and 
throughput over software-based RAID because it is independent of the system processor.A seperate disk controller handles the data creation and 
regeneration of redundant information. Whereas in software-based RAID, the creation and regeneration of data is handled by a utility called 
Disk Management which is a system process.
NOTE: RAID-5 volumes are not available on some operating systems, but most Server operating systems directly support software-based RAID.

Installing RAID is a personal preference, below are some suggestions:
*Business Servers should be set up to use some sort of RAID system, either hardware or software- based because interruptions to data access 
  can be both costly and crippling to a business.
*Workstations that are used for intensive work should have a RAID system set up.
*Regular PC's usually do not need RAID due to the nature of the work,  but that doesn't mean you can't have RAID.

Do you need to back up a RAID drive?
Absolutely! RAID  should be backed up just like any other hard disk.
Backups remain vital.
Below are instructions for a software-based RAID backup.

 Software-based RAID
 
I recently installed Windows 2000 Server and created a SCSI RAID-5 volume using Disk Management.
Install a minimum of three hard disks and  a SCSI controller.
Install a Server OS that can support RAID.(Most Server OS systems support RAID, Novell 6.0 doesn't support software-based RAID but Novell 6.5 will ).
Once the server OS has been installed, open Disk Management.
If you need to delete previous partitions, do that first, now it will bring it to 'unallocated' space.
Next upgrade to Dynamic Disk.
Then Create Volume
Select Volume Type- RAID-5 Volume
Select the Disks--add all available dynamic disks.
Assign a drive letter to your new volume.
Format the volume.
Ready to use.

Backing  Up The RAID Volume

Within the Windows 2000 Server environment there is a backup utility which is located at:
Start/Programs/Accessories/System Tools/Backup
Choose the Backup Wizard /What to back up / Where to store the back up / 
I chose to backup to the new volume D:\ , if you have a tape device , you can choose to backup to that. 
You can also use RAID as a backup device for other volumes.

Additional sources of information:
www.microsoft.com
www.techweb.com
http://www.networknewz.com/2002/1028.html