That's a good idea.
Conventional wisdom is keep the data on a separate partition, but the computer I have in malware help came close to losing the 3rd partition, which is the largest and holds the most of my data.
So my next bright idea was separate hard drives in the same computer, but then I read an article that said that's not safe because a power supply short can kill both hard drives. Oddly enough, that happened to me last year. In all my years of power supply failures, I've only had to buy a new one. This time cost me two HDD.
I used to have an external USB HDD for data backups. Then my UPS let me down last year when a big short (lightening-like arc about a foot long) on a nearby power pole fried the HDD.
So now I am using the LAN to swap files between computers for backup.