What Are Levels Of RAID 0, 1, 5? Which One Is Better And Why?

Redundant Array of Independent Disks (RAID) is the combining of several hard drives into a single unit.  There are a number of RAID levels, among them the most popular are: 0, 1 and 5, which require controllers to support them. Two or more disc drives are combined and the result is fault tolerance and good performance. These disks drives are usually ,used on servers and there is no need for them on personal computers.

Level 0 is used for applications, which do not require redundancy or striping. Which, means the contents of the files are spread out over the multiple disks. One of the common uses for level 0 is in editing digital video. In level 0 there is not falut redundancy, and if one drive happens to fail all the data is lost.

Level 1 is used for applications, which include critical data and referred to as mirroring. RAID 1 is fault tolerant in situations when a drive fails the system will continue to work. Level 1 provides twice the transaction rate of single disks.

Level 5 is used when fault tolerance is needed and uses block level striping and distributed parity. When one disk drive in RAID 5 goes down the data is recovered using the remaining drives. RAID 5 is considered, to be the most popular RAID level in use today, because of it's performance, redundancy and storage efficiency.

There is also a version of RAID known as RAID 10 which gives one both the advantages of RAID 1 with the speed of RAID 0.  RAID 10 consists of a Striped Array like in Raid 0 or Raid 5 (without the parity drive of course) but also duplexes both of the those striped drives.  

So if one has a stripped array of two drives RAID 10 would take a total of 4 drives.  The advantage of such a configuration is both speed and redundancy with no downtime.  If a single drive fails, the system should not even notice and most systems will allow on-the-fly drive replacement.  That way one can simply install a new drive and it will "scrub" in the background with no noticeable latency.  If two drives fail at the same time, depending on the scenario, no data loss should occur, but a there could be a slight impact to latency.

In to the RAID 5 how much dive we can use