It seems to be common sense that you should consider scaling up MDM architecture as your 1:1 grows. However, it took us a little longer than expected to move this direction. My shop currently uses the Casper Suite by JAMF Software. It does a really good job, but like anything, it gets hungry for more resources as it grows. We currently manage over 9,000 iOS devices and about 500 assorted MacBooks. Our MDM is running on a single Windows VM. Most days it works fine. Devices check in, policies are pushed out. Apps can be pushed out to a grade or two on specific campuses without issue. 
However, it does hang up considerably when pushing anything out to the entire group. Also, Casper Focus (a classroom management app from JAMF) can sometimes hang or be unresponsive. As more and more features have become available for iOS MDM management, the load on the server has also increased. With the release of 9.3 and the Apple Classroom app, it was obvious that we needed to scale up.
New MDM Architecture
We decided to do a little research and increase resources for our MDM. The people at JAMF were pretty helpful and pointed us to Killeen ISD who manages at least twice the number of devices we do. We used their basic design with a few changes resulting in the following: multiple JSS Instances on different VM servers sit behind a load balancer and communicate to a fourth server running the database. All while all other servers are VMs, this one is a dedicated box. We spent a little extra to future proof it and make sure it had plenty of resources. Next, a separate JSS instance has the web interface turned on and is used for management tasks only. It is not behind the load balancer and is never communicated with by the devices. Last, there is a separate file share for OS X devices, also outside the load balancer.
We are still in the process of installing and configuring the new servers. I hope to write about the increase in performance that scaling up MDM architecture provides us in future posts.
