Is JeOS a Tonic for VM Sprawl?
It seems that everyone is worried about VM sprawl these days. When system capacity is easy to consume because the application is prepackaged as a virtual machine (a virtual appliance in the case of an ISV), the virtual infrastructure capacity is quickly gobbled up by those that have been waiting for IT to get around to provisioning systems for them. No more friction due to virtualization means no more waiting and wanting. It also leads to VM sprawl. But why is VM sprawl bad?
VM sprawl is bad because the scale of the management problem used to be throttled by the capital spending associated with the size of the infrastructure. Now, the scale of the management problem is equal to the true demand for application capacity as represented by the number of application images, or virtual machines, that get deployed. This scale factor associated with application images throws the old yardstick of X system admins per Y server machines out the window. What are we going to do to lower the work profile associated with so many new systems that now need to be managed?
I think at least part of the tonic for VM sprawl is the new acronym coined by Srinivas Krishnamurthi of VMware – JeOS. JeOS stands for Just enough OS and it is pronounced “juice.” In my mind, this liquid pronunciation is appropos given my view of its potential potency as a tonic for VM sprawl. A huge part of the burden of system management is the patching and associated regression testing for maintaining the security and functionality of the general purpose OS. If you can shrink the size of the OS by 90% (which is where we have measured the typical size for most applications built with our rBuilder technology) by eliminating any elements not required by the application, you can eliminate about 90% of the patching burden. More importantly, you eliminate the bigger burden of regression and stability testing that is coupled to the patching process.
With a JeOS approach, the number of virtual machines can theoretically grow by 10X the legacy approach without any impact to the cost structure associated with patching and testing the OS changes. I suspect a 10X reduction represents a real win for most shops as the OS patching and testing associated with security and infrastructure performance is a very sizable portion of their management spending. So if you are feeling the pangs associated with VM sprawl, I strongly suggest a healthy slug of JeOS each morning and once again in the afternoon to clear your system of the painful bloating that is brought on by virtualizing the general purpose OS.