Thursday, March 4, 2010

Investigation for a setup

Continued from: More Virtualized Machines

We have a couple of older servers that have had me rather nervous for some time. One of these servers has started giving us a temperature alarm on the hard drives every morning. This is exacerbated by a building management company who don’t seem to understand that turning on a fan to bring in colder outside air can cool the building significantly without running the expensive HVAC compressors… but that is a topic for another time. The over temperature problem highlights another potential benefit of virtualization: “reduced heat loads.” If you are running more of your computing resources on fewer computers, then you are more than likely generating less heat in your computer room.


These older servers amounted to about $12,000 of new computer equipment to replace them. If I could figure out a way to set up a virtual infrastructure that is only marginally more than the $12k that we have to spend anyway, then we would have the following benefits:

  • Lower heat load
  • Easy expansion to additional (virtual) servers without purchasing additional hardware
  • Additional benefits of the purchased / licensed version of VMWare
  • Less rack space taken up than by stand alone servers
And so, I began my quest for the perfect entry level VMWare infrastructure. My first stop was my local technology support shop. They had helped me set up a web server load balancing tool using a Radware box in the past. I sat down with them to describe where we were, and where we wanted to be. They came back about a week later with a quote for $97,000. I considered that significantly more than marginally above $12,000. Scaling back my expectations and sending them back to the drawing board returned some quotes on the order of $45,000. Much better, but it was still not enough return on investment in my opinion. It was time for me to do some shopping on my own.

When I venture into uncharted territory, I like to do some reading to learn just how much I really don’t know. The first book that I picked up was “vSphere 4.0 Quick Start Guide.” It was more of a cookbook for how to do specific things as opposed to an introduction to VMWare, though it will probably come in handy down the road. The second book that has been very helpful was “Mastering VMware vSphere 4” by Scott Lowe. This book described all the little tools available with vSphere, system planning, installation tips and scenarios, and detailed information about configuration once you were up and running.

One of the main things that I learned was that I wanted to have a storage environment that is shared between multiple hosts. In general terms, I was looking for a Storage Area Network (SAN). I found out that the major flavors come in Fiber Channel, iSCSI (Internet Small Computer System Interface), and SAS (Serial Attached SCSI).

Fiber Channel turned out to be the most expensive, but typically a higher performance option than iSCSI or SAS. SAS and iSCSI were fairly close in price, but SAS was a little faster performing than the typical 1 Gig Ethernet iSCSI solution. There are 10 Gig Ethernet iSCSI solutions, but those were significantly higher in price.

Coming next: Contact with vendors.

Tuesday, March 2, 2010

More virtual machines

Continued from: Virtualization Adventure

I was now successfully up and running with VMWare ESXi 3.5. (Version 4 wasn't out yet.) Things went so smoothly with setting up my first machine, I couldn't wait to try another. It didn't take long for the next opportunity to arise.

I have some machines that I need to connect to remotely. They are located on the networks of other organizations, so I have no control over the VPN mechanism by which I connect to these systems. As a result, I have the "privilege" of utilizing Novell, Cisco, and Citrix to access these various machines. As you can imagine, there are some challenges with using all of these vpn clients. I found that if I installed both the Novell and the Cisco client on the same machine, the result was that neither of them ended up working. The Citrix client would connect from my system, but then it wouldn't run the RDP (remote desktop protocol) to pull up the remote server. If I connected to either the Cisco or the Novell vpn servers, then all of my local connections would be severed thereby causing any local jobs that require network access to crash.

The solution (prior to virtualization) was to have 2 machines dedicated to vpn client connections. (Citrix plays nicely with either one, so I could just run my Citrix connections from either of these machines.) The difficulty arose from my VNC (Virtual Network Connection).  VNC allows you to look at the desktop of a computer on your network without having to sit in front of the physical machine.  I tried connecting to these virtual machines via VNC, and then connecting to the VPN servers.  The problem was, once I was connected to the VPN servers, it severed my local connections, thereby disconnecting my VNC so I couldn't access the client computer.  Our workaround was to use a Raritan KVM solution that was awkward at best.

Virtual machines to the rescue!  I set up 2 Windows XP vm's.  One for Novell and one for Cisco and Citrix.  I no longer had the problem of losing my kvm, because the VMWare client has its own console program that works very nicely.

Other virtual machines quickly followed: a backup domain controller, a legacy Windows 2000 server box that we needed to run some old image processing software, and a dedicated workstation for one of our remote employees to use.  None of these were really mission critical operations so all was running nicely, even without redundancy in this setup.

Coming soon: Investigation for a step up

Virtualization Adventure

Taking the dive into the world of virtualization is no small feat. What platform should I use? How should I set up storage? What servers will work for me? Where do I begin? These questions barely scratch the surface of the information you will need to venture into the world of virtualization.

My adventure began with a brief exposure to virtualization while attending a Cisco networking introductory class in 2004. The instructor had a small network of virtual computers all running on his laptop to demonstrate correct and incorrect network environments. I thought it was pretty cool at the time, but didn't have any practical application for that myself.

Fast forward to 2009. I work for a small company in which I wanted to experiment with some linux functionality using Fedora. I didn't want to dedicate a full workstation or server to these experiments. I remembered the cool virtualization concept and decided to play. I started with Microsoft's virtualization server since we are primarily a Microsoft shop. This solution didn't require a dedicated server. The setup was easy, but the Fedora build didn't seem to work smoothly, so I tried VMWare's ESXi Server 3.5. (Both Microsoft's and VMWare's server versions are free.)

I did have to bite the bullet and re-task an older server since ESXi does require a dedicated server. They do have a workstation build that you can install on top of an existing windows build, but that was only a trial version, and I didn't feel like having to go through a purchase or a reinstall if I decided to continue using it. The setup was fast, easy, and Fedora went in seamlessly. I was now committed to VMWare over Microsoft.

My reasoning behind this decision was:
  • VMWare worked easily with Fedora and Microsoft didn't.
  • VMWare has been working with virtualization for years while Microsoft is a relatively new contender.
  • VMWare ESXi is the host operating system, while Microsoft still requires that you have an underlying operating system running to support the virtualization environment.
Coming next: More virtual machines!