Two of our three ESX servers got rebooted last night at around the same exact time.
(1:30 AM in the morning)
I thought that it might be power outage , just checked .. they are using different power outlets.
Is tehre any built-in auto-upgrade or a process that can cause this ? how can I figure the root cause ?
log file shows that host enters maintenances mode :
VpxdMoHost::UpdateConnectionStateInt] <ESX IP > Marked as dirty.