AiHua Information Technology Site

First, I must remind everyone that most of what goes onto the blog is meant for small to medium sized businesses (SMB) or similarly sized NGOs unless otherwise stated.  For example, I have no qualms about placing an ebox server into an organization up to one hundred people but would seriously consider doing a hand installation of separate openldap, gateway, mail server, jabber, and file servers for organizations of two hundred or more.  This article is such an article about methods for the less than 100 users organization and may not be a good method of setting up servers that have high input and output demands as they may be better served by iscsi, das, or e-sata.

That being said, in the world of 1 Gig switches and ethernet cards, it is easy to create links between computers that ping in less than 0.003 milliseconds.  This is easily fast enough to hold a redundant RAID array of hard drives on a network attached storage drive that shares files to a second, third, or even fourth server accessing those files.  Since a virtual machine is merely a folder and set of files it is trivial to house files on the raid array and then share those files via NFS to more powerful machines that actually host the virtual machines.

The advantage of housing your VM’s in a single location and having multiple virtual hosts is that it is possible to shift virtual machines to make the best utilization of server resources.  The simplist way to achieve this setup is to equip each server with at least two 1 gig ethernet cards and then create direct crossover connections between the NAS and vm hosts like so:

VMHost1<—NAS—>VMHost2
|                           |
——-Switch——–
|
Local Area Network

Remember to have each ethernet set have a different IP set (192.168.1.0 for hosts to switch, 10.0.1.0 for VMHost1 to NAS, 10.0.2.0 for VMHost2 to NAS, etc).  If one of the hosts becomes overloaded or crashes it’s possible to migrate virtual machine to the other now!

For added reliability in the system it’s possible to use a heartbeat to make a redundant NAS setup; however, that is beyond the scope of this article.  Good luck with your own VMHost-NAS, use the “Contact Us” page if you need to discuss help and support options.

It seems that in the virtualization race that a couple of relatively new entrants are making headway.  The first, proxmox, works much like a hypervisor for xen.  It actually runs on a modified Debian linux, making it quite similar to one of our favorite distributions in the office: Ubuntu linux, which is also based on Debian.  It’s a true open source project that also supports openvz guests which have a speed advantage but are restricted in which operating systems can be virtualized.

The second new development comes from Sun Microsystems who is soon going to offer an open sourced virtualization server which is also based on xen.  This one will be a hypervisor based on OpenSolaris (which is a tried and true unix variant and makes our list of favorites with Ubuntu and OpenSuse) and thus features some of the fantastic features that Solaris variants have.  The most exciting of which is native support for the most advanced file system available: ZFS.  It will also feature interoperability with their acquired technology from VirtualBox (an open source product I heartily recommend to desktop users who need or want virtualization) and has a vastly improved interface compared to previous interface attempts by Sun Microsystems.

These technologies will make implementation and installation much quicker and significantly simpler for organizations to achieve.  It will also make deployment of virtualized appliances (such as those offered by AiHua) easily installed by persons with minimal technical know how (as configuration can be primarily achieved by IT personnel prior to distribution).  They also seem to support many more hardware configurations than the often expensive name brand servers that ESXi seems to prefer.

To discuss the feasibility and potential benefits and side effects you can use the contact page to engage our consultation services.