Our Linux instances running on Amazon EC2 had no issues since we are not running ntpd on these servers and adjtimex returns status as 64 (clock unsynchronized).

Our Linux instances running on Amazon EC2 had no issues since we are not running ntpd on these servers and adjtimex returns status as 64 (clock unsynchronized). I think the Xen host takes care of the synchronization and we need not do it in the guest OS. (see http://serverfault.com/questions/100978/do-i-need-to-run-ntpd-in-my-ec2-instance http://serverfault.com/questions/100978/do-i-need-to-run-ntp...). Is this fine or should we run ntpd for better accuracy?