13-02-2013, 04:49 PM
What is raid?
RAID is the term used to describe a storage systems' resilience to disk failure through the use of multiple disks and by the use of data distribution and correction techniques. RAID stands for:
Redundant Array of Inexpensive or Independent Disks
Software and / or Hardware
RAID can be Software, Hardware or a combination of both. Generally speaking, Software RAID tends to offer duplication or mirroring, whilst Hardware RAID offers Parity-based protection
Software RAID uses more system resources as more disk ports and channels are required and it is subject to additional load during write and copy operations. Software RAID may have a lower cost than hardware RAID because it has no dedicated RAID controller, but may not have the same hotfix or performance capabilities. Software RAID is needed for mirroring to remote locations.
HARDWARE RAID
Hardware RAID offloads Parity generation and checking from the host, and also leaves the host unaffected by internal operations such as rebuilds. Hardware RAID allows for greater disk capacity per disk port. Hardware RAID requires the expense of a RAID controller per subsystem. Hardware RAID systems themselves can also be mirrored with software mirroring.
Hybrid RAID Levels:
Some hardware vendors provide hybrid RAID levels combining features of the original RAID levels. Three of the most common hybrid levels are RAID level 10, RAID level 30, and RAID level 50. RAID level 10 is hybrid RAID level that combine mirroring with striping. RAID level 30 and RAID level 50 are hybrid RAID levels that combine parity RAID techniques with data striping
RAID is the term used to describe a storage systems' resilience to disk failure through the use of multiple disks and by the use of data distribution and correction techniques. RAID stands for:
Redundant Array of Inexpensive or Independent Disks
Software and / or Hardware
RAID can be Software, Hardware or a combination of both. Generally speaking, Software RAID tends to offer duplication or mirroring, whilst Hardware RAID offers Parity-based protection
Software RAID uses more system resources as more disk ports and channels are required and it is subject to additional load during write and copy operations. Software RAID may have a lower cost than hardware RAID because it has no dedicated RAID controller, but may not have the same hotfix or performance capabilities. Software RAID is needed for mirroring to remote locations.
HARDWARE RAID
Hardware RAID offloads Parity generation and checking from the host, and also leaves the host unaffected by internal operations such as rebuilds. Hardware RAID allows for greater disk capacity per disk port. Hardware RAID requires the expense of a RAID controller per subsystem. Hardware RAID systems themselves can also be mirrored with software mirroring.
Hybrid RAID Levels:
Some hardware vendors provide hybrid RAID levels combining features of the original RAID levels. Three of the most common hybrid levels are RAID level 10, RAID level 30, and RAID level 50. RAID level 10 is hybrid RAID level that combine mirroring with striping. RAID level 30 and RAID level 50 are hybrid RAID levels that combine parity RAID techniques with data striping