Re: Run OS X 10.9 from a separate partition in a VM?

First create a normal Mac OS X 10.8 64-bit Virtual Machine without installing the OS.

Then use "/Applications/VMware Fusion.app/Contents/Library/vmware-rawdiskCreator" to create a meta-data .vmdk (virtual hard disk) pointing to the external hard drive.

Then manually swap out the empty virtual hard disk in the Mac OS X 10.8 64-bit Virtual Machine created earlier for the one created with vmware-rawdiskCreator and edit the .vmx configuration file to reflect the change.

Also while editing the .vmx configuration file add the following option to it as well.

suspend.disabled = "TRUE"

Also note that in addition to not suspending, which the above option does, one also should not take Snapshots (or use AutoProtect) with physical disks!