What are Disk Arrays


What are Disk Arrays

Disk arrays are storage systems that link multiple physical hard drives into one large drive for advanced data control and security. Disk arrays have several advantages over traditional single-disk systems.
A hard disk, while being the vital center of any computer system, is also its weakest link. It is the only critical device of a computer system that is not electronic, but relies on intricate moving mechanical parts that often fail. When this happens, data is irretrievable and unless a backup system has been employed, the user is out of luck. This is where disk arrays make a difference.
Disk arrays incorporate controls and a structure that pre-empts disaster. The most common disk array technology is RAID (Redundant Array of Independent Disks). RAID utilizes disk arrays in a number of optional configurations that benefit the user.
One advantage of RAID disk arrays is redundancy of data writes so that if a file is damaged or stored in a bad cluster or disk, it can be instantly and transparently replaced from another disk in the array. RAID also allows hot-swapping of bad disks and increased flexibility in scalable storage. Performance is also enhanced through a process called "striping."
There are many varieties of RAID, and though designed primarily for servers, disk arrays have become increasingly popular among individuals because of their many benefits. RAID is particularly suited for gamers and multimedia applications.
What are Disk Arrays


RAID controllers, built into motherboards, must set parameters for interacting with disk arrays. The controller sets the performance parameter to match the slowest disk. If it were to use the fastest disk as the benchmark, data would be lost when written to disks that cannot support that speed. For this reason, all disks in the array should be the same brand, speed, size and model for optimal performance. A mix of capacities, speeds and types of disks will negatively impact performance. The best drives for disk arrays are SATA (Serial ATA) RAID drives. These drives are optimized for RAID use and, being SATA, are hot-swappable.
Using disk arrays can provide peace of mind while improving data security and performance. Motherboards with built-in RAID controllers support certain types of RAID. For example, an older or inexpensive motherboard might only support RAID 0 and RAID 1, while a newer or more expensive board might support RAID 1 through RAID 5. Be sure to get a motherboard or third party RAID controller that supports the RAID configuration you require for your disk array.

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