xgrr.de – the whole not the half

In professional areas virtualization of servers and workstations enables us to evaluate operating systems and software packages in an isolated environment and without great costs. But this is still the starting point of virtualization. As our current internet topology and software applications ask for integration – the Cloud is a good keyword here – we have to be not only able to virtualize physical PC hardware but also provide network environments which are abstracted from our current internet.

This would enable network engineers, system administrators and of course scientists to easily develop new network infrastructures, test distributed deployments or invent new protocols on top of the network stack. The impact of a commercial virtualization technology for networks would have a huge impact of the way we currently build networks.

With the development of NGN (Next Generation Networks) this idea is pushed by a few selected but until now it did not surface to the broad public.

Update: I made a bit of research on the topic. Nothing deep really but I still found some interesting material:

• Network Virtualization: a strategy for de-ossifying the internet
• Cisco gives virtual servers virtual networking

I also found a lot of sites talking about network virtualization in connection with classic computer virtualization. This is only a part of what is meant. Network virtualization should be an end to end implementation with virtual nodes on the end points itself in the form of a software or firmware on the NIC and also on the nodes in between. It has not necessarily be linked to virtualized servers although this would of course make a lot of sense.

Recently I visited the social network Hyves which is very popular in the Netherlands and saw and job offer for a system engineer/administrators position. In the comments to this position there was harsh critics about the network of Hyves which consists currently of about 1700 servers running Gentoo Linux.

When I read more about the infrastructure I realy wondered why they need 1700 which results in A LOT of money for operation and maintanance. I’m not the only one who said this but the tone was different than my . I saw a thread about virtualization which is working very well recently for non real-time applications.  And Apache, MySQL or whatever they use as a backend is not real-time.

However they reason the choice for a lot of servers with the need for I/O throughput (when you read my blog closely you will see that I/O performance is the big problem when working with virtualization). What I wondered so much is that no post mentioned the use of SAN. They certainly have something similiar otherwise I don’t want to know how they store all the data they gather. So why don’t they use it for virtualization? Good SAN provide a lot of needed I/Os as well as redundancy. When using in combination with NFS (very upcoming – SANs are mostly connected by using iSCSI) the bottleneck of low I/O operations is decreased.

I for myself run VMware very successfully. With a good plan and VMware Infrastructure 3 or something similiar a consolidation of the needed servers can be done and the overall costs decreased.

I love VirtualBox because is fast and without a lot overhead. But network bridging is kind of pain in the ass with VirtualBox . I hope they change this fast. Anyways I had to convert my VirtualBox images to the VMware file format. This is easily done with qemu-img a nice tool bundled with qemu. It can handle serveral file formats:

 Supported format: qcow2 vvfat vpc bochs dmg cloop vmdk qcow host_device raw

So you could convert some other stuff too. Converting is easily done (this example is for Windows by using qemu-0.9.0-windows):

 qemu-img.exe convert -O vmdk hdd.vdi hdd.vmdk

In this case we convert the disk hdd.vdi to hdd.vmdk. The input format is detected automatically but can be overriden by adding -f switch. Output is vmdk as given with the -O switch.