Well, it's been a few years and we haven't switched it back. :) We have had a number of clock issues, and one of the first things I try is taking and instance

Well, it's been a few years and we haven't switched it back. :) We have had a number of clock issues, and one of the first things I try is taking and instance and switching it back to xen for a few days, but those issues have not turned out to be the clocksource. Usually NTP. AWS can comment more about the state (safety/risk) of these clocksources (given they have access to all the SW/HW internals).