My company needs to add another virtual windows server to an existing Esxi server and I need to get a handle on how may users can run rdp sessions.  

The Esxi server is a Dell PowerEdge T620 12 cpus x 2.899 GHz, Intel Xeon, 2 CPUs with  49106.48 MB of memory.  The hard drive capacity is 800 plus gigs.

Right now we have a MS server 2008r2 running along with a Red Hat Linux server and the CPU resources are just a tiny bit on the cpu resource scale and the memory is running around half of the total memory.  The hard drive usage is around half total as well.

I'm not familiar enough with servers or server software to have any idea of what we can add in without bogging down all of the servers.  We need to run around 50 rdp sessions with the possibility of Microsoft office on most of them.  I'm trying to find out if we can do this with the current hardware or should I be looking at getting another server to handle the new load.

Help?

you should tell the resource you have available for the new server (total resources minus the ones you are already using for the other VMs)

I'd plan 1.5 GB per user and 4 for the OS, but it's just a rough estimation, 2 virtual CPU could do the job.

Disk space depends on your ne

you should tell the resource you have available for the new server (total resources minus the ones you are already using for the other VMs)

I'd plan 1.5 GB per user and 4 for the OS, but it's just a rough estimation, 2 virtual CPU could do the job.

Disk space depends on your ne

It might work well with 700 MB per user, it all depends on the utilization, you mentioned office, I assume outlook+word+excel and maybe some browser tab.

Have a look how much these applications take on a session, you can do that on your client.

It might work well with 700 MB per user, it all depends on the utilization, you mentioned office, I assume outlook+word+excel and maybe some browser tab.

Have a look how much these applications take on a session, you can do that on your c

Your answer is pretty difficult to answer in a forum like this because we really don't know, nor can we measure, the exact workload you have.  Nor can we measure what adding additional users to the system will do.  By that I mean we can't say if your existing system will scale linearly or will find a 'hockey stick' somewhere out there.  You really need to run your own benchmarks and measure.  Fortunately there are tools that can be used to generate loads that simulate a 'working' Microsoft Office environment.  You could load up one of those to and run different combinations of workloads on the system to see how it scales.  Login VSI is a such a tool that comes to mind.

You could also run Microsoft MAP tool (www.microsoft.com/map) against your existing environment and try extrapolating the results to see what you might need.  That tool has some capabilities of actually loading in known server configurations and 'expanding' a workload to extrapolate what it might look like in production.