Messaging Gateway on VMWare has time drift issues

Products

• Messaging Gateway

Issue/Introduction

• The VMWare host and SMG are both configured to set the system time.
• There is severe time drift or resets of server time that cannot be easliy explained.

Environment

SMG

VMWare ESXi 5.0+

Cause

When a VM host and guest OS both compete to control system time, anomolies can be introduced. In VM environments, this can either be done with the VM's daemon, or the client OS' daemon. Most virtualization experts agree the client OS should handle NTP. VMWare recommends that the guest OS time daemon controls the system clock.

Resolution

Disable time sync in VMWare host

For VMWare hosts, follow the steps in Timekeeping best practices for Windows, including NTP (1318) from VMWare. The section "VMware Tools Time Synchronization and Configuration" (section applies to any operating system) provides different ways to configure the VM host to disable time sync.

Configure NTP or manual time in SMG

• Refer to Set date and time of a Messaging Gateway host manually for manual date/time config in SMG, or
• Recommendations for NTP configuration to configure NTP servers.
• Use the steps in Messaging Gateway clock drifts even though NTP is configured to restart the services needed after time configuration.