synctime

Time synchronization in VMware guests

Have you ever been in this situation where the recommended solution is overly complex for a simple thing you want to do ?

Well, for a few months we have had issues with time synchronization on VMware guests. This is an old ESX 2.5 environment with fairly recent operating systems (RHEL4.6). The recommended way is to use clock=pit as a kernel boot parameter and to enable Host-Guest clock synchronization by either using vmware-toolbox (GUI!) or changing the .vmx files. In both cases a reboot is required for the time synchronization to kick in.