Is it possible to run Mountain Lion on older hardware by using a virtualization solution?

Solution 1:

10.7.x or 10.8 (Build 12A269) in VirtualBox

There's an answer under How can I install Mac OS X Lion in VirtualBox, or any other type of virtual machine?.

I guess, a .vdi of Mountain Lion produced in that way will be usable with at least some Macs that might not otherwise run the OS.

Example

Physical machine:

• MacBookPro5,2 with 8 GB memory
• VirtualBox 4.2.0 Beta 1.

In the VirtualBoxVM:

• Build 12A269 of OS X 10.8
• without FileVault 2
• with Core Storage encryption of something other than the startup volume
• dynamic_pager disabled:

Alongside an answer to Why would I disable swap file in Mac OS X?, note that without swap files, Activity Monitor measures both:

• virtual memory size
• page ins.