Why we are still need to do backup our system and data regularly even we have hardware RAID1 or RAID5 or whatever RAID level and RAID type configured on our server ?
While most RAID levels are designed to reduce the chance of data loss due to hardware failure, it is still possible to lose data on RAID arrays. Here are a few examples where RAID does not protect against data loss:
-)The drive controller in your system fails and writes random data to multiple disks in your RAID array, corrupting it.
-)The controller cache on your RAID controller fails and writes corrupted data to your disks.
-)The motherboard or RAM fails on your system and causes corrupted data to be written to your disks.
-)Multiple disk failures occur in your RAID array, rendering the array unrecoverable due to corrupted data and/or parity bits.
-)Physical damage to the computer occurs and renders the disks unusable.
-)The computer and its RAID array are stolen.
-)A user accidentally deletes files.
So what are you waiting for? start back up your valued data ,do not 100% depends on hardware RAID and software RAID anymore!
Cheers 
