HDD Raid security

Short answer: No.

Longer answer: There are specific reasons to use specific levels of RAID. None of them are a substitute for backups (brief bow to rgd1101). Unless using RAID to address a specific need or for the sheer joy of playing with it, don't get it. In the latter case (sheer joy option), be prepared to lose everything on it frequently as you mess with configuration and testing.

Ooh - I just tried to link to one of my old posts on RAID and the link is dead.