I used to think I had a decent setup for data redundancy until a hardware failure occurred after moving my work PC from one office to another. The service technician found the motherboard to be at fault and quickly replaced the bad part with a new one. Not knowing I had my drives set up in a RAID 1 mirror he didn’t set it up the RAID controller properly. About a week later when I noticed the extra drive showing up on the “My Computer” screen, I notified our IT department of the issue and they sent someone out to fix it. That is when my world crashed. The mirror was so far out of sync that when he put them back together it wiped everything out and reinitialized (so the tech told me).
Sure wish I had an external backup solution then!