A power surge here where I am may kill the power supply. It's low probability that it would kill everything. Anyway, I don't fear the lightnings/storms/power s

A power surge here where I am may kill the power supply. It's low probability that it would kill everything. Anyway, I don't fear the lightnings/storms/power surges where I am as much as I do the inevitable failures of the storage devices, or kernel bugs. This is just a part of layered protection I have. Offline backups are nice, and I have them too, but they are out of sync all the time by definition. So unless absolutely needed, having a real-time synchronized replica is much more prefered.