Exacq recently announced a VMWare appliance exacqVision Virtual VMS Software for VMware host video servers | Exacq
In a discussion in the old LinkedIn group, an Exacq product manager posted a detailed technical explanation, copied below: "Here are several important points related to virtualization that we learned while creating our VMware certified exacqVision virtual appliance. * Most physical servers are greatly underutilized, so virtualization can reduce hardware costs. Our server application is very CPU/RAM efficient, so we were able consolidate 4 physical servers into one virtualized server (128 vs. 512 cameras). If you use a VMS with server side motion detection, then the ratio is lower because more CPU power is required. Some video analytic packages don't virtualize because they offload video analysis to the GPU, which virtualization abstracts from the application. * Virtualization is great if you need high uptime. Jayson mentioned High Availability, which will restart your guest (application) from a failed host to an operational host. Think 5 minute failover. For a lot more money, Fault Tolerance will transfer your application to another host in a second or two using memory mapping. * Any brand of VMS will require significant disk I/O capacity to write/read large volumes of data. You can measure your disk I/O on a current physical server in MBps, then consult with your iSCSI provider to determine the IOPS (Inputs/Outputs Per Second) rating required of your storage system. A general rule of thumb is adding all of your incoming camera traffic (remember to convert from Mbps to MBps), add on 25-50% for video searches, plus any other overhead required by your VMS for maintenance. If you're building your own storage system, run a third party disk benchmarking program like Sandra on your host to measure throughput to the SAN to make sure you're in the ballpark before going live. - Virtualization requires a moderate/high level of technical competency to maintain. It only took us hours to get our software initially working in VMware, but weeks to build a completely stable, maintainable virtual appliance with all the "gotcha's" worked out. If you use VMware, I strongly suggest having a system engineer with a VCP (VMware Certified Professional). Virtualization software is like any other complex software in that there's a significant learning curve that may not be obvious at first."