>>1489461>RAID backupRAID is not backup.
Its purpose is to ensure system reliability in spite of drive failure.
(Except RAID 0, whose purpose is to speedrun losing all your data.)
It makes sense for a server that needs to be online 99.99999% of the time.
But it makes less sense for a home user who just wants to protect their data.
Because the error that is likeliest to happen isn’t hardware error.
It’s not software error either.
It’s human error.
You’re gonna overwrite the wrong file, delete the wrong file, misplace some files in the wrong spot.
RAID won’t help you with any of that, because it’ll instantly mirror all these fuck ups.
What you need is the ability to go back in time.
And only a sync made at a prior point in time gives you that.
Not only that, but running drives at the same time is noisy, and it wastes power.
They’re also very likely to fail around the same time, due to the equal wear.
As such, the remaining drive could easily crap out during the hours (if not days) it takes to rebuild the array.
Contrast that with an offline backup, where the backup drive hadn’t been running for anywhere near as much.
Now, depending on how long ago the sync was made, some changes will be lost.
As a home user, that’s not such a big deal.
You just gotta build the discipline to sync the backup whenever you’ve made changes you can’t afford to lose.
Ultimately, having both RAID mirroring and backups would be best, but that becomes expensive.
