Security Analyst – Jeff Soehner CISSP, GXPN,GPYC,GMOB,GCIH

After we rebuilt a new workstation for the office we were able to start experimenting with some new disaster recovery ideas. These tests would involve some of the new VM server configurations and Xenserver 6 has made it to the top of my list.

Once of the issues with VMservers that everyone has is updates. It’s quite a benefit running more than one server on a single piece of hardware but it’s quite another when you have to patch the VMserver and take them all offline too!

One of the nice features of the new Xenserver 6 is that upgrades to the pool of VMservers can be done using the XenCenter console with the push of a button. Everything from uploading the patches to rebooting the VMservers is done for you.

We tested our first patch on two fresh installs of XenServer 6 and the process took about 8 minutes from the start to the finish.

We then imported a VM into the master and updated the pool again with two patches in succession to see the time it would take to migrate the VM back and forth to maintain the uptime. Unfortunately this product does not allow migrations when using local storage. Even when we took into consideration the time to suspend the VM and spin it up again the patches only took 15 minutes.

Lastly we moved the storage to an NFS host (FreeNAS) and created shared storage. We added another patch and started the process while we left the lab. The updates took less than 10 to reboot the same machines AND migrate the working XP machine from one server to the other.  Best of all is the uptime – there was no appreciable lost of available IP as shown in this simple ping test.

(Notice the point when we began the migration from one server to another in the pool is shown by the increase in time to approx. 10ms)

I really like the ability to run VMs with maximum uptime and that is good news for small business owners and support personnel like myself. That means we don’t have to patch at 4 in the morning anymore!