zlacker

I believe a more plausible scenario could be that each drive failed during the RAID rebuild and restriping process.

This is a known issue in NAS systems, and Freenas always recommended running two raid arrays with 3 disks in each array for mission critical equipment. By doing so, you can lose a disk in each array and keep on trucking without any glitches. Then if you happen to kill another disk during restriping, it would failover to the second mirrored array.

You could hotswap any failed disks in this setup without any downtime. The likelihood of losing 3 drives together in a server would be highly unlikely.

https://www.45drives.com/community/articles/RAID-and-RAIDZ/

>>hoofhe+(OP)
Ideally, there should be redundancy in servers, too.. With different hardware, on different sides of the planet, on different service providers.

>>pmoria+IC
Correct.. Your production server with dual mirrored arrays should have an identical warm spare. If it's in the same data center, then you need a separate offsite backup in case of a worst case disaster such as a tornado, fire, or nuclear strike.

>>hoofhe+(OP)
Unless it was due to end of life, or power surge related failure.

Then more than one failing simultaneously isn't so inconceivable.