I don’t see how even this would help in the case of a physical HDD failure. When the drive goes SCREEEEECH that’s it, game over.
I’ve had ‘benign’ failures (MBR corruption) that were easily fixed with a free utility called Partition Table Doctor, but two times in the past 15 years drives went physically bad, and that was that.
From my perspective physical HDD failure is what I’m scared of, and the only option is, of course, regular backups.
Various RAID options are also suppose to minimize HDD failure consequences....as I understand it.
It's got a volume manager, so it can be configured to include redundancy to protect against HDD loss(es).
If you're worried about losing a disk and you're running Linux, you've got a couple options without zfs, either mdadm or LVM.
I don't think there's a software option included with the home user versions of Windows, but you could just get a cheap RAID1 card and do it in hardware, if your motherboard does not support it.
ZFS is really meant to be used with arrays of drives and just like a hardware RAID controllers, it generates EDAC (error-detection and correction) data and spreads it across all the drives in the array. Using the EDAC data an entire drive can be rebuilt. The penalties being about 20% extra space used by the EDAC data and it being painfully slow to rebuild a big drive.
ZFS also has a bunch of other features including live drive snapshotting. For a more of a “backup” type of feature.
But, the features are really more about “uptime” then about backing up. Just like in RAID5 or RAID6, you can have one or two drives in an array completely fail and ZFS will stay up while rebuilding the replacement drive(s). And you’re more likely to know when a drive is starting to act wonky than with a hardware RAID controller due to the extra testing that ZFS does.
All that being said, ZFS is big resource hog if you need all it’s fancy features. For example, IIRC, they recommend a minimum of 1GB of RAM for every 1TB of drive space when using all the features. So the RAM requirements are pretty hefty for a large array. And it pays to have an blindingly fast CPU with lots of cores if you ever have to rebuild a drive.