So far, the best solution available would be Xen, but other good solutions would be OpenVZ and Linux VRF. Linux VRT provides separate networks profiles for processes, so that one process can have some interfaces, firewall rules and routing table, while other processes will be associated with other devices and tables. OpenVZ is a containers solution (something like Solaris Zones), where this isolation between processes is not only done at the networking level but at an OS level, with their own node name, virtual network interfaces, storage, etc.

Xen is not the best performer. The performance problem comes from the overhead introduced by systems calls: when a guest VM sends a packet to the network, it has to be processed by the guest machine, make a context switch and be processed again at the host OS. As a result, network performance is not as good as a native machine, but its is still one of the best in its class.

However, Xen is probably the best supported solution in the market nowadays. There are a lot of configuration tools, web interfaces, and some network simulation tools. For example, MLN looks like a nice application for creating virtual networks: you have to define the topology in a very simple configuration file, and you get a bunch of Virtual Machines connected with virtual LANs, hubs, routers and so.

So I have decided to give a try to ccache. ccache is a program that caches object files produced by gcc. When you run it instead of gcc, it takes the pre-processeed source file, the arguments and some other things, and calculates a hash code. Then it runs gcc as usual, but it also copies the .o (with the hash code) to a cache directory. Next time you try to compile the same source file (and with the same gcc arguments), it checks if the hash code is the same and, in that case, it quickly returns the .o you compiled before.

It is a good idea, but I’m not really sure if it will make any difference. Yesterday I tried it for a while, but I couldn’t say my build was speed-light fast…. I will keep trying.

The website of a Miami-based networking and security solutions reseller became inaccessible Monday, shortly after the company began advertising an unauthorized Mac clone for a fraction of the cost of Apple’s cheapest system. Dubbed OpenMac, the USD 400 offering from Psystar Corporation is described as ‘a low-cost high-performance computing platform’ based on the ongoing OSX86Project - a hacker-based initiative aimed at maintaining a version of the Mac OS X operating system for everyday PCs. The website is back online now, and the machine has been renamed to Open Computer.

I would like to see some alternatives to the hardware sold by Apple (or a reduction in the price of the original hardware), but I’m not sure how many problem you will run into if you try to run OS X on this. And, honestly, it doesn’t look nice.

There is an anti-pattern that I’ve seen in large organizations which I have come to call “the Dead Sea effect”. [...] Many large corporate/government IT shops — and not a few small ones — work like the Dead Sea. New hires are brought in as management deems it necessary. Their qualifications (talent, education, professionalism, experience, skills — TEPES) will tend to vary quite a bit, depending upon current needs, employee departure, the personnel budget, and the general hiring ability of those doing the hiring. All things being equal, the general competency of the IT department should have roughly the same distribution as the incoming hires.

But in my experience, that’s not what happens. Instead, what happens is that the more talented and effective IT engineers are the ones most likely to leave — to evaporate, if you will. They are the ones least likely to put up with the frequent stupidities and workplace problems that plague large organizations; they are also the ones most likely to have other opportunities that they can readily move to.

Slideshow of my travel to New York. Five days in the Big Apple. You can see the complete set of pictures here.