I agree with G.G.
and for backup use a backup program with compression and scheduling capabilities (or alternatively use batch files and Windows scheduling with a backup program that has command-line options like Macrium Reflect...which is what I do). Between the redundant parity protection of RAID6 and a robust backup protocol you'll be in good shape.
In addition, locate your backup drives in their own power subsystem and protections and you improve your resistance to a single-point catastrophic failure taking out your main and backup drives. You could even distribute the backups amongst other systems in your network.
Here's an example using MacriumReflectFreeEdition and a .bat file using Windows scheduler to create a daily backup of the system drive. Note that MRFE allows you to create .xml backup macro files that control how the backup occurs (e.g. with or without compression, "intelligent" backup or full content, where the backup is to be stored, etc ). These .xml files are created AUTOMATICALLY for you by MRFE when you perform the first backup and you can re-use them from then on, so you do NOT need to know how to write any code to make them.
For example, you might setup Windows scheduler to run this .bat file at 2AM every morning.
echo off
REM Daily Drive C backup batch file using Macrium Reflect Free Edition
REM Ver 201008070443
REM Dependencies
REM T:\DriveC_DailyBackup_MR.xml backup definition file created under MRFE
REM MacriumReflectFreeEdition (verified under Ver. 4.2.2952)
REM delete old dailiy backup image file to make room for new daily image
del T:\DriveC_DailyBackup_MR\*.mrimg /Q
REM temporarily set execution path to include Macrium
path = %path%;C:\Program Files\Downloaded_apps\MacriumBackup
REM The specified .xml file is an "intelligent", "medium compression" backup ("intelligent"=no pagefile/hiberfile)
REM -e = execute the .xml file, -w = if MR busy then wait until available
reflect.exe -e -w "T:\DriveC_DailyBackup_MR.xml"
REM Daily Drive C backup batch file using Macrium Reflect Free Edition
REM Ver 201008070443
REM Dependencies
REM T:\DriveC_DailyBackup_MR.xml backup definition file created under MRFE
REM MacriumReflectFreeEdition (verified under Ver. 4.2.2952)
REM delete old dailiy backup image file to make room for new daily image
del T:\DriveC_DailyBackup_MR\*.mrimg /Q
REM temporarily set execution path to include Macrium
path = %path%;C:\Program Files\Downloaded_apps\MacriumBackup
REM The specified .xml file is an "intelligent", "medium compression" backup ("intelligent"=no pagefile/hiberfile)
REM -e = execute the .xml file, -w = if MR busy then wait until available
reflect.exe -e -w "T:\DriveC_DailyBackup_MR.xml"
edit to add:
And, you can create weekly and monthly .bat files that save the appropriate files on the obviously weekly and monthly basis, and clear out older copies once a time threshold has passed. For example, you might only want to keep the last 4 weekly backups (for a 1 month recovery capability with weekly granularity), and only keep the last 6 monthly backups with monthly granularity, and so on. And you might want to make sure a given set of backups (e.g. the monthly set) is located or copied to a location completely off-site. Of course how deep and granular you make it depends on just how critical your data and programs are and your disaster planning and recovery protocols.