[ Thanks to Ken Hess
for this link. ]
“$$$. Maintenance Window Reduction – Virtual machines need
maintenance but if you multiply the amount of time required to
reboot individual physical systems by the number of years you
service a system, the number is significant. Granted that this
number is mostly Windows-oriented because patching of Linux and
UNIX systems typically don’t require reboots.
Regardless of the operating system involved,
you’ll save labor hours waiting for systems to
return to a usable state. VMs generally reboot in five minutes or
less, while their physical counterparts can take almost a half
hour—depending on attached hardware and system
services involved in startup.”