I’ve gotten feedback on my last blog update on this subject and here’s the scenario:
- The parent OS requires 512MB (MINIMUM) but you should allow for 2GB (recommended).
- Hyper-V itself requires 300MB but it’s likely the 2GB assignment will compensate for this (in most cases).
- Drivers and agents on the parent might push your requirement for more than 2GB.
- Each VM requires at least 32MB for the 1st GB of RAM. Each additional GB of RAM for the VM requires (at most) 8MB for each additional GB of RAM. MS say 8MB to be conservative. Only if the VM is trashing RAM will you hit this 8MB.
- The second VM will require 32MB for it’s first plus another 8MB (max) for each additional GB of RAM.
So here’s a typical scenario:
- Parent Partition: 2GB (but you might need another 200 for Hyper-V and more for drivers/agents)
- 2GB RAM VM: 32MB + 8MB
- 4GB RAM VM: 32MB + (3 * 8)MB
- 1GB RAM VM: 32MB
Thanks again to Dave Northey and John Howard who took the time to dig internally in MS to help me with this problem.
Credit: Dave Northey and John Howard.