I just lost all my code. All of it. And I deserve it because I didnt back up my files. Daily reminder, don't be like me, back your important shit up.
If you're dumb enough not to use a subversion control system, and a RAID hard drive array, on top of 3 remote back ups taken every hour, then you're a brainlet and your code was shit.
RAID 1 IS NOT A BACKUP
If something gets corrupt, that corrupt information is replicated to both drives, meaning you're still boned. There are also a litany of other potential issues, depending on how the RAID was set up (software RAID vs. hardware RAID, synchronization issues, corrupt volumes, etc.)
RAID 1 is good for better up-time in mission critical environments, but it is NOT a backup solution.
A controller card specifically designed for RAID will always be preferable to cost-saving corner-cutting compatible-with-everything type controllers that are on most motherboards.
The controller on most motherboards is a cheap chip meant for compatibility with as many drives as possible. When you're compatible with everything, you lack the ability to specialize. If you can't specialize, you lose performance and operating quality which leads to higher risk of data corruption and/or loss through poor volume management. Also they often store the RAID information in their own configuration rather than on the disk, so if the motherboard ever has an issue (like the battery going dead) you can lose all your RAID information and therefore data.
Controller cards are purpose-built for this task and counter the above, save for those that also store all the RAID information on-chip rather than on the hard drive.
Oh, I almost forgot - you can also create a software RAID through your operating system. This generally works fine in most scenarios, though you don't have fine-tuning control and your RAID mode options are limited, but most people don't need to do more than what the operating system provides. The primary down side is if you have to connect the drive(s) to another computer, it's gotta be the same operating system. Other than that it generally works pretty well.
Unless you use OS X - It's RAID 0 or RAID 1 and that's it. And OS X 10.11 removed the ability to manage RAID through its disk utility - has to be done entirely in command line now.
I don't get it, why isn't the redundancy in a RAID1 good enough for a backup? Because if both drives fail simultaneously somehow, or if there is a house fire, everything is lost? If I just want a backup for my movie and music collection, isn't that enough?
This thread reminded me to back up my sorely aging 250GB HDD. Slowness is due to crappy 2008 hard drive. Thanks, OP.