Many businesses use RAID (Redundant Array of Inexpensive Disks) technology as a safe, efficient means of data storage. Below are some of the most common types of RAID server configurations and how their designs affect data loss and recovery.
RAID 0 - RAID 0 is not truly a type of RAID, since it doesn't provide redundancy. RAID 0 systems can consist of any number of drives. Data is striped across drives, so if any drive fails, the RAID owner loses data. However, RAID 0 arrays are extremely fast, so they are an appropriate choice for high-speed applications in which redundancy is not important.
RAID 1 - The simplest type of RAID, RAID 1 uses mirroring. The system writes identical sets of information to two locations at once. If a drive fails, the owner can replace it easily, restoring the array without data loss.
However, RAID 1 systems are inefficient and can become costly. They are not ideal for web servers or high-end storage systems, although they can work well for small-scale redundant storage. Many RAID 1 systems consist of only 2-4 drives and are designed for small office or home use.
RAID 3 - RAID 3 consists of a minimum of three drives. Data is written in parallel to at least two drives, while the final disk contains parity information used to restore the array after a data loss event. These arrays can lose a single HDD without losing any data or functionality.
RAID 5 - RAID 5 also requires 3 or more drives. Unlike RAID 3, there is no dedicated parity disk. Parity information is stored on each drive of the array, which makes RAID 5 a faster and more cost-efficient option. RAID 5 systems also write information independently to each disk.
RAID 5 is the most common type of RAID configuration for web servers, NAS, SAN and other large-scale storage devices.
RAID 10 and Other Hybrids - For enhanced redundancy, many businesses use RAID systems that utilize multiple RAID configurations simultaneously. A RAID 10 array, for example, is a RAID 0 with RAID 1 protection. For a four-drive configuration, this would mean two two-drive sets with identical striped information.
RAID 6 is probably the most common. It uses a double distributed parity in addition to block-level striping, so it is a more reliable option than RAID 5. It is also more expensive, and most RAID 6 arrays are used in enterprise environments. In contrast, RAID 2 and 4 are less efficient and typically less reliable than RAID 5 and have fallen out of favor as a result.
While some RAID configurations are safer than others, we receive all possible types of RAID configurations from clients across the country every year. RAID systems fail for a number of reasons including failed rebuilds, which can occur when a RAID member fails due to extra stress created by the rebuild process. User error accounts for a significant percentage of data loss on larger RAID systems, and power failure is also causes thousands of RAID failures each year.
For the best possible protection, you should regularly back up important RAID data in at least two offsite locations and immediately contact a RAID data recovery provider at the first signs of data loss.
We offer reliable RAID data recovery for all configuration levels. Call 1-800-388-1266 for more information.