> TL;DR: Power outages are more common than your colo facility will admit. Seconded. I've seen power failures in at least 4 different facilities and all of them had the usual gamut of batteries/generators/etc. Some of those facilities I've seen problems multiple times in a single year. Even a datacenter with five nines power availability is going to see > 5m of downtime per year, and that would qualify for the highest rating from the Uptime Institute (Tier IV)! I've lost power to Ceph clusters on several occasions, in all cases the journals were on spinning media. -- Kyle
 |