I've got four 2TB HDD's I want to back them up. Please help.

This is what you do. 

You are going to need a lot of disk. 1, get yourself an external RAID that supports 4, 3TB drives (12TB total) back all your data off to there. Next,  you are going to want to get a fith 2TB drive to put everything into RAID 5. Make sure your OS is on a seperate disk. Go to your RAID controller and put your drives together into a RAID 5, leaving all the default settings. Go back into windows or whatever OS you are using and format the disk. If you are using windows, make sure to install Intel Rapid Storage Technology so that you have proper raid support inside the OS. 

Now move all your data back onto the RAID 5 and keep the external RAID as a backup.

That is the easiest solution you can ask for, but it is not the cheapest. Sorry bro. 

Also, I don't really use RAID 1, It is slow and inefficent. With RAID5, what you do is you use RTS to keep an eye on your disks and also have something like Crystal Disk Info to keep an eye on things as well. Regularly check the smart data on the drives (at least once a week). The likelyhood of 1 of 5 drives failing is high, but to have 2 drives fail is rather low. 

With the external RAID, you can have your data backed up in 2 spots. I personally like the MediaSonic boxes. 

EDIT: If you are using the Intel RAID built into the board, use RTS, if you use the PERC or anything else, you are going to want to use whatever software comes with that. Otherwise you could have some issues. 

Quote:

Originally Posted by Subzero11 

If I go with raid 1 or 5, how does it know if a HDD has partial failed or say files get corrupted cause of a bad sector will a message on the desktop to tell me HDD drive Z: has failed please replace ? How does it know and how will I know something went wrong ? thanks

1. Buy 2 or 3 more 2TB HDDs I wouldn't recommend WD greens for this. i would look into hitachi/seagate/ WD reds.
2. Buy a perc 5/i or 6/i
3. Make a RAID 5 array with the free drive and the new drives
4. Then copy your data you want to back up over to the new RAID 5 array.
5. The you can either leave it as a backup or you can expand your current drives into the array if you like.