ntp對時 = > date command is not work

4.6. Time handling in Linux VMs
By default, the clocks in a Linux VM are synchronized to the clock running on the control domain, and cannot be independently changed. This mode is a convenient default, since only the control domain needs to be running the NTP service to keep accurate time across all VMs. Upon installation of a new Linux VM, make sure you change the time-zone from the default UTC to your local value (see Section 4.8, “Release Notes” for specific distribution instructions).

[root]# cat /proc/sys/xen/independent_wallclock
0 => Linux VM are synchronized to the clock on VM Server.
1 => Linux VM can be set to maintain independent times.

Individual Linux VMs can be set to maintain independent times
1.From a root prompt on the VM, type the command: echo 1 > /proc/sys/xen/independent_wallclock
2.This can be persisted across reboots by changing the /etc/sysctl.conf configuration file and adding:
# Set independent wall clock time
xen.independent_wallclock=1