| Redundant Arrays of Inexpensive Disks (RAID) | | | | limited size drives. |
| was introduced to increase the level of | | | | |
| storage, redundancy and augmented performance | | | | Enhanced Performance |
| in enterprises and server markets, but now | | | | |
| have become much common with an end user over | | | | Improved performance can be found in specific |
| the past 5 years. | | | | versions of RAID and this performance depends |
| | | | upon the number of drives used in the array |
| In simple terms, RAID can be defined as a | | | | and the controller. Different RAIDs when |
| combination of number of low cost hard drives | | | | implemented provide superior performance in |
| linked together to form a single large | | | | their own way and up to different levels, but |
| capacity storage device with improved | | | | all improve in some way or the other. |
| performance, high storage capacity and | | | | |
| reliability of data storage. Use of RAID | | | | Lower Cost |
| storage technology came into significance in | | | | |
| late 1980s and has marked its presence as the | | | | When RAIDs were introduced, the cost of |
| in-demand data storage medium for corporates, | | | | implementing them became a key issue. The |
| professionals, manufacturing units and | | | | invention of RAID was to provide greater |
| individual users for their need of high | | | | storage capacity as compared to use |
| capacity data storage device. | | | | individual high storage capacity device. |
| | | | Difference in the cost of high and low |
| Generally three forms of RAID are used for | | | | capacity drives can be analyzed with a good |
| desktop computer systems - RAID 0, RAID 1 and | | | | example where three drives of small size cost |
| RAID 5. | | | | less than an individual high capacity drive |
| | | | which provides more capacity. |
| RAID 0 is the lowest level of RAID. This | | | | |
| level fails to provide any level of | | | | Data Security |
| redundancy for the data stored in array. If | | | | |
| any of the drive fails, all the data is | | | | The data which is stored on array is |
| damaged. | | | | completely secured as RAID provides complete |
| | | | security and competence to protect the data. |
| RAID 1 provides simple form of redundancy for | | | | This security is followed even if the |
| data with the help of mirroring process. This | | | | complete hard disk fails without any data |
| RAID level has two individual drives with | | | | loss or performing the restoration process of |
| same capacity. One is the active drive and | | | | the backed up data. All RAID levels provide |
| the second is secondary drive termed as | | | | same degree of data security. |
| mirror. When data is written to the active | | | | |
| drive, it automatically gets copied to the | | | | Improved Accessibility |
| mirror drive. | | | | |
| | | | Accessibility refers to availability of data. |
| RAID 5 is the most powerful and effective | | | | RAID provides its users to recover data from |
| level of RAID used on desktop computer | | | | hardware faults without any problems. |
| system. It requires hardware controller card | | | | |
| to manage the array but in some desktop | | | | Disadvantages of RAID: |
| operating system it can be done through | | | | |
| software. | | | | RAIDs do give an assured security to the |
| | | | computer systems but this security cannot be |
| A minimum of three drives are required to | | | | relied upon for long time. If your PC gets |
| build RAID 5 array with similar drives for | | | | attacked by virus, or files and folders are |
| best performance. | | | | deleted or your PC hits the floor or is |
| | | | affected by the fire - water damage leads to |
| Other levels of RAID levels are RAID 0+1, | | | | such situations where you don't have any |
| RAID 10 or 1+0, software and hardware RAIDs | | | | other option other than opting for RAID data |
| which are used for the storage of data. | | | | recovery services. There have been many cases |
| | | | when more than one drive has failed causing |
| Advantages of RAID: | | | | an expensive RAID data recovery. |
| | | | |
| Redundancy | | | | Like such cases, anything is possible and |
| | | | constant backups should be maintained to |
| Redundancy becomes the most important feature | | | | avoid data loss situations even if you are |
| while developing the RAID server environment. | | | | using any reliable storage medium. |
| Redundancy is required in means of performing | | | | |
| backup of data in situations of drive failure | | | | Conclusion: |
| in the array. | | | | |
| | | | It is agreed that RAID provides PC users with |
| Capacity | | | | a number of benefits depending upon the |
| | | | version implemented. High storage capacity, |
| By combining multiple small drives into a | | | | security, accessibility, performance are the |
| large array, capacity to store large amount | | | | key features which attract users to opt for |
| of data increases. The data storage | | | | RAID. The advantage of one RAID level over |
| capability of the operating system increases | | | | the other cannot be measured as for some |
| as the RAID server is installed thus | | | | applications RAID 5 is better than RAID 0 and |
| providing you the freedom to store any amount | | | | for some RAID 0 would be superior to RAID 5. |
| of data which gets restricted while using the | | | | |