- Striping – RAID 0
- Mirroring – RAID 1
- Striping & Parity – RAID 5
- Striping & Double Parity – RAID 6
- Combining mirroring and parity – RAID 10
Striping – RAID 0
Although it is classified as a RAID level, RAID O is in fact not fault tolerant. As such, RAID O is not recommended for servers that maintain mission-critical data.
RAID O works by writing to multiple hard drives simultaneously, allowing for faster data throughput. Striping RAID give a significant performance increase over a single disk but, as with a single disk, all data is lost if any disk in the RAID set fails. With RAID O you actually increase your chances of losing data compared to using a single disk because RAID 0 uses multiple hard disks, creating multiple failure points.
Basically, you can use more disks for the RAID 0 array but A minimum of two disks is required to implement a RAID 0 solution.
Mirroring – RAID 1
RAID 1 is perfect for a fault-tolerant configuration known as disk mirroring. A Mirroring RAID solution uses two physical disk drives. Whenever a file is saved to the hard disk, a copy of the file is automatically written to the second disk. if any failure The second disk is always an exact mirrored copy of the first one.
Striping & Parity – RAID 5
RAID 5 is the most popular and common use secure RAID level. Striping and parity RAID requires at least 3 drives but can work with up to 16 drive.
RAID 5 Data blocks are striped across the drives and on one drive a parity checksum of all the block data is written. The parity data are not written to a fixed data drive, they are spread across all drives, as the picture below shows.
Using the parity data, the computer can recalculate the data of one of the other data blocks, should those data no longer be available.it’s means a RAID 5 array can withstand a single drive failure without losing data or access to data that thy RAID 5 is best choice.
Striping & Double Parity – RAID 6
Striping and Double parity means is like RAID 5, but the parity data are written to two drives like double data blocks , it’s means requires at least 4 drives and can withstand 2 drives dying simultaneousły. Probably, chances are very small two drives break down at exactly the same moment are same time.
if any a drive in a RAID 5 systems fail and is replaced by a new drive, it takes some hours or even more than a day to replace drive If another drive failure during that time, you still lose all of your data but the RAID array will even survive that second failure With RAID 6.
Combining mirroring and parity – RAID 10
Combining mirroring and parity RAID it’s possible to combine the advantages and disadvantages of RAID 0 and RAID 1 with one single systems. RAID 10 is a nested or hybrid RAID configuration. It provides security all data on secondary drives while using striping across each set of driven to speed up data transfers.