How To Understand RAID, RAID Level 0, 1 And RAID Concepts.
RAID (redundant array of independent disks) is a way of storing the same data in different places on multiple hard disks or solid-state drives (SSDs) to protect data in the case of a drive failure. There are different RAID levels, however, and not all have the goal of providing redundancy.
Raid are used when we need excellent performance. According to our selected raid level, performance will differ. Saving our data by fault tolerance & high availability.
Software & Hardware RAID.
Software RAID have low performance, because of consuming resource from hosts. Raid software need to load for read data from software raid volumes. Before loading raid software, OS need to get boot to load the raid software. No need of Physical hardware in software raids. Zero cost investment.
Hardware RAID have high performance. They are dedicated RAID Controller which is Physically built using PCI express cards. It won’t use the host resource. They have NVRAM for cache to read and write. Stores cache while rebuild even if there is power-failure, it will store the cache using battery power backups.
RAID 0, 1 (striping and miroring)
Striping have a excellent performance. In Raid 0 (Striping) the data will be written to disk using shared method. Half of the content will be in one disk and another half will be written to other disk.
There is Zero Capacity Loss in RAID 0
Zero Fault Tolerance.
Write and Reading will be good performance.
Mirroring have a good performance. Mirroring can make a copy of same data what we have. Assuming we have two numbers of 2TB Hard drives, total there we have 4TB, but in mirroring while the drives are behind the RAID Controller to form a Logical drive Only we can see the 2TB of logical drive.
Here Half of the Space will be lost in total capacity.
Full Fault Tolerance.
Rebuilt will be faster.
Writing Performance will be slow.
Reading will be good.
Can be used for operating systems and database for small scale.