For our physical and virtual servers, we have settled on certain naming schemes. If you add a new server, please remember this.
For these, we've opted to pick names of chemical elements. For clusters, we usually take three elements next to each other. There is no policy which elements to take, usually we use the ones that sound nice.
For VMs, we use Discoverers of chemical elements, again without any order. There are a few exceptions though: some names of our servers are not from these discoverers (reason unknown), and some servers have their names connected to their role (e.g. mail1).
Please find the map of currently used names in the System Hackers' documentation, which can be found on their team page.