I don't know your specific scenario, but the odds of simultaneous disk failure is already really low, especially if you use two different brand drives with different manufacturing dates.
The way I've seen most deal with this is to have three drives with one designated as a hot spare, and the controller will automatically handle duplicating data immediately to the spare when a failure is detected.
For handling multiple drive failures I think you'd have to look at using something like RAID 10.
In either case, if you're worried about your critical data, you need a GOOD backup in place to recover data if there's a crash or error on some component that takes down the server. A hundred drives duplicating data won't help if the controller or motherboard or memory goes wonky (or your server is struck by lightning or pretends to be an anchor when a pipe bursts).
RAID isn't a panacea. I have had a RAID 5 array warn of a disk failure. During the rebuild when replacing the dead third drive, a critical error on a second disk, UNDETECTED, prevented a rebuild from completing. The drive controller would run repair after repair on the second disk and insist it was okay only to fail again.
There is a writeup about why today RAID 5 is worthless and RAID 10 was the way to go now. Basically with drives being so large there are a certain number of tolerated failed readable spots on the disk and as they get bigger the odds of encountering one of those spots increases, thus scenarios like mine get more common. A drive has an undetected error at a moment that is critical to recovering from an error. dead in the water. In my case we had to recover from bare metal from a backup. Lost just a couple days of files fortunately.