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Virtually Starting Over


By DaveAtFraud - Posted on 01 August 2011

The old Athlon 64x2 I had been using as my VMware server was having more than a little trouble running a virtual server and several virtual clients for my IPv6 tests and experiments. Although the hardware was not on the VMware compatibility list, the only thing I had to do to make it compatible was to install an Intel gigabit ethernet card and VMware installed and worked well. I decide that something with more cores and more RAM would probably "greatly enhance" my VMware experience so I bought an AMD Phenom II x6 CPU and supplied it with 16GB of RAM on a Gigabyte motherboard. Big mistake.

Everything appeared to be fine after the transplant. The first indication that there was a problem came from some of the automatic e-mails like those generated by logwatch. They started showing up in my Inbox at all sorts of odd times. I investigated and found that the system clocks for my VMs had all gone loopy.

I made sure that NTP was installed on all of the VMs and it was correctly configured. Sure enough, after not even a day the clocks were off significantly. I then checked the VMware clock and it was off. I went through several iterations of setting the server clock through the BIOS and then using hwclock and date to monitor the clock drift from the VMware maintenance console. The hardware clock seemed to keep reasonable time but the system clock drifted all over the place (e.g., several seconds every minute). After quite a few Google searches for different combinations of VMware and "clock drift" I finally gave up.

The system is still serving the same purpose but is now running Scientific Linux 6.1 (CentOS 6 was slow to appear when all of this was happening). I am now running a similar collection of VMs under KVM instead of VMware. All I can say is that KVM does a much nicer job of virtualizing the guest video than VMware and I no longer need the old Windows XP box I was using as the VMware management console. The host OS (Scientific Linux) is its own management console.

On the dowside, I don't have the VMware virtual switch and virtual network management tools. This probably means I'll be learning a lot more about setting up bridging under Linux. The default network setup under KVM is fine for just virtualizing a collection of systems but I haven't found a way (yet) to configure network traffic between the guest VMs on the host server. Looks like that is my next "learning experience."

Cheers,
Dave