The name ‘RAID’ is nowadays getting more familiar to most people looking for a NAS-device or server usually for business or home use. The term stands for Redundant Array of Inexpensive Disks. All RAID enabled systems will use two or more hard disks to enhance performance or cater for fault tolerance issues. The fault tolerance aspect is important as a way of providing a kind of a safety net in case of hardware failure. It will ensure the continued operation of the machine with a component failure such as the hard drive.
The RAID levels determine the way you will configure the fault tolerance. The levels all depend on the number of disks available in the storage device, the seriousness of the drive failover/recovery in relation to your overall data needs and its importance to performance enhancement. A home user needs are different from that of a business in that the latter has more reasons to maintain the data intact when a hardware failure occurs. The different levels associated with RAID always represent different configurations. The difference main aim is to provide different balances in data protection and performance improvement.
In order to get to understand the different levels, we will embark on the review to try to give an overview of the differences that exist between RAID 0 and RAID 1 as a start.
RAID 0– The level offers to strip without parity or mirroring. Stripping is the act of data being split evenly across the available disks.
RAID 1– The set up for this is quite different in that there is no stripping and the whole data will be mirrored on each of the disks. The problem with this is that it will result in multiplications causing redundancy.
RAID 1– There is more reliability at this level than level 0 due to the data redundancy factor. The argument is that, even if one drive fails there will still be data available on the remaining disks. The only disadvantage is that the RAID arrays will not offer protection against data bit rot.
RAID will offer faster writes and reads than RAID 0. The write times are enhanced by the data split over the several disks. The transfer speed of arrays determines the speed of transfer to all disks combined. Reads from RAID 0 are done at a lower speed as performance is slowed down by its controller. The performance of RAID 0 is therefore considered better than that of RAID 1.
When it comes to total available storage-
-For RAID O unit, it is the sum of separate disk storage capacities due to none redundancy.
-For RAID 1, it is the same for the entire disk because of redundancy
RAID 1 is the best choice in terms of reliability and no- data loss. RAID 0 will be the best choice in cases where volumes are large and high performance is required.