It is now a common rule of thumb that when you are building Virtual Server Infrastructure (VSI), you must assess your physical environment with analysis tools. The analysis tools show you how to fit your physical workloads onto virtual machines and hosts.

The golden standard in analysis tools is VMware’s Capacity Planner. Capacity Planner used to be made by a company called AOG. AOG was analyzing not just for physical to virtual migrations, but was doing overall performance analysis of different aspects of the system. AOG was one of the first agentless data collections tools. Agentless was better because you did not have to touch each system in a drastic way, there was less chance of drivers going bad or performance impact to the target system.

Thus, AOG partnered with HP and other manufacturers, and was doing free assessments for their customers, while getting paid by the manufacturer on the backend. AOG tried to sell itself to HP, but HP, stupidly, did not buy AOG. Suddenly, VMware came from nowhere and snapped up AOG. VMware at the time needed an analysis tool to help customers migrate to the virtual infrastructure faster.

When VMware bought AOG, VMware dropped AOG’s other analysis business, and made AOG a free tool for partners to analyze migrations to the virtual infrastructure. It was a shame, because AOG’s tool, renamed to Capacity Planner, was really good. Capacity Planner relies solely on Windows Management Instrumentation (WMI) functions that is already built into Windows and is collecting information all the time. Normally, WMI discards information like performance, unless it is collected somewhere by choice. Capacity Planner just enabled that choice, and collected WMI performance and configuration data from each physical machine.

When VMware entered the Virtual Desktop Infrastructure (VDI) business with Horizon View, it lacked major pieces in the VDI ecosphere. One of the pieces was profile management, another piece was planning and analysis, another piece was monitoring. Immediately, numerous companies sprang to life to help VMware fill the need. Liquidware Labs (where the founder worked for VMware) was the first to come up with a robust planning and analysis tool in Stratusphere FIT, then with monitoring tool in Stratusphere UX. Lakeside SysTrack came on the scene. VMware used both internally, although the preference was for Liquidware.

Finally, VMware realized that the lack of analysis tool for VDI, made by VMware, was hindering them. But what they failed to realize, was that such tool already existed at VMware for years – Capacity Planner. The Capacity Planner team was neglected, so rarely would any updates were done to the tool. However, since Capacity Planner could already analyze physical machines for performance, it was easy to modify the code to collect information on virtualizing physical desktops, in addition to servers.

Capacity Planner code was eventually updated with desktops analysis. All VMware partners were jumping with joy – we now had a great tool and we did not have to relearn any new software. I remember that I eagerly collected my first data, and began to analyze the data. After analysis, the tool told me I needed something like twenty physical servers to hold 400 virtual desktops. Twenty desktops per server? That sounded wasteful. I was a beginner VDI specialist then, so I trusted the tool but still had doubts. Then I did a few more passes at the analysis, and kept getting wildly different numbers. Trusting my gut instinct, I decided to redo one analysis with Liquidware FIT.

Of course, Liquidware FIT has agents, so I used it, but always thought that it would be nice not to have agents. So VMware’s addition of desktop analysis to agentless Capacity Planner was very welcome. So, back to my analysis, after running Liquidware FIT, I came up with completely different numbers. I don’t remember what they were – perhaps 60 desktops per physical server, or something else. But what I do remember was that Liquidware’s analysis made sense, where Capacity Planner did not. My suspicions about Capacity Planner as a tool were confirmed by VMware’s own VDI staff, who, when asked if they use Capacity Planner to size VDI said, “For VDI, avoid Cap Planner like the plague, and keep using Liquidware FIT.”

As a result, I kept using Liquidware FIT since then, and never looked back. While FIT does have agents, now I understand that getting metrics like Application load times and User Login delay is not possible without agents. That is because Windows does not include such metrics in WMI. Therefore, a rich agent is able to pick up many more user experience items, and thus do much better modeling.