What is RAID ?

RAID Explanation

 

 RAID is a way to get protected from hard­disk failures.
 An example of RAID ?
Let'simagine the three directors of Coca­Cola company.
 If one of them knows the entire production secrets, he might build his own company. If each of them knows only the third of the secret, as soon as one dies, the product is lost.

So, let's divide the product secret in three: part A, B and C. Director 1 knows secret A, director 2 knows secret B and director 3 knows secret C. 

For redundancy reasons, let's learn to director 1 the secret B too, to director 2 the secret C and to director 3 the secret A.
In this case, none of them knows the entire production method, but any of them might die, the remaining knows what to learn to the newly hired director. 

The only thing we know about hard­disks is: they will die.
But no one's know when.
 If you want your data to survive your hard disk, use RAID (as Linux provides you for free). You will have the opportunity to replace your crashed hard­disk and see the system rebuild the missing data without even stopping you to work !