Part of my job is network administration of a small (~50 server) colo/hosting service. It's unacceptable for us to be down for even 30 minutes (from our perspe

Part of my job is network administration of a small (~50 server) colo/hosting service. It's unacceptable for us to be down for even 30 minutes (from our perspective and our clients). We maybe top out at 5 hours of downtime a year (during a bad year) and most of that (unfortunately) is upstream from us.