SUMMARY
Timekeeping on VMware UEB
ISSUE
Purpose
Define the best practice for timekeeping inside the VMware UEB.
Description
If deploying to a VMware hypervisor below ESXi 5.0, VMware recommends that ntp be used as your primary source of time synchronization for the guest VM (in this case the VMware UEB). The VMware UEB allows for setting up ntp when using the Configuration Wizard or through the Settings > System, Updates and Licensing > Date/Time menu in the Web UI.
Starting with ESXi 5.0, it is now acceptable to use VMware Tools time synchronization. Since VMware Tools time synchronization uses the ESXi host as its source of time, the ESXi host must also have time synchronization enabled.
In either case, starting with Unitrends Enterprise Backup (VMware) version 7.4.0, the VMware UEB will default to using VMware Tools time synchronization if ntp is not setup on the VMware UEB. If ntp is setup inside the VMware UEB, then VMware Tools time synchronization will be disabled. Note that VMware recommends that only one method of time synchronization be used.
Third-Party Sources
VMware Knowledge Base Disabling Time Synchronization (1189)
VMware Knowledge Base Timekeeping best practices for Linux guests (1006427)
VMware Timekeeping in VMware Virtual Machines