LaoBlog

Clock problems on virtualbox virtual machinese

I recently found out that one of my Linux virtual machines on a Debian Virtualbox host was quickly losing the right time. Because it happened after an update, at first I though there was something wrong with the ntp daemon, but I was wrong. Because that trouble occurred only on one of my virtual machines, i didn't suspect that the problem could reside in the virtualization system. However, some time ago, because I had experimented another problem on Virtualbox: the excessive consumption of cpu resorces by a VM. Looking for a solution, somebody suggested to build a new virtual machine with a very low reseurces request. Therefore I build a freedos machine which, following the above suggestion, should be started before any other.

Curiously, by investigating the clock problem, I realized that I didn't start the Freedos machine after the last update of both guests and host. Therefore I stopped all the VMs, start the Freedos, and then the others. Magically, the clock problem has disappeared...

Anyway, remember to regulary update the virtual guest's addiction, when prompted by Virtualbox, because this could affect the clock syncronization between host and guest.