virtualbox.org

I looked and didn't see this question anywhere. I have some Macs and Wins on a network and I want to store all the VM files on a central location (like a NAS drive) for security and manageability. If a Mac creates a VM with certain features (like VT-X turned on or maybe 2G of memory allocated) and a Win computer that doesn't have that ability (like no VT or not enough RAM) tries to run the VM, do I have to change the affected feature each time and keep track of the settings? It's probably a stupid question, but I'm not sure how a mixed environment should be handled with newer and older computers. Using VB 3.2.12 now, but might upgrade to VB 4 if that would be better for this.

The two different hosts can't exchange their config like that. What you set in OSX isn't visible in Windows and vice versa. You can create two VMs that share the same VDI, but if you try to boot them at the same time, or have varying settings, things can go very wrong.

Yes, I would create a VM on each machine and they would share the same VDI, as you mentioned. I would not boot them both at the same time, only one at a time. But do all of the settings in each VM have to be set exactly the same (like the same amount of RAM allocated or things like that) or can each VM have different settings even if they share the same VDI? The Mac has lots of RAM and a newer CPU while the PC does not, so that's why I would need to have different settings for each VM but share the same VDI.

The VM settings have to be set for the least capable Host (the weakest link).

russff wrote:But do all of the settings in each VM have to be set exactly the same (like the same amount of RAM allocated or things like that) or can each VM have different settings even if they share the same VDI?

That isn't really a VBox question. VirtualBox itself doesn't care what settings (like amount of RAM) a VM has - it's only the guest OS which might care. IMHO, the short answer to your question is that you should try to make the (virtual) hardware as similar as possible on all hosts.

mpack wrote:it's only the guest OS which might care.

That makes sense, I was thinking more about VBox than the guest. To keep the settings to the "weakest link", that would mean creating the VDI on the weakest link? Some settings like VT-X are available on my Mac host but not the PC host, so if I create the VDI on the Mac, this setting gets turned on by default and then causes problems if I use the VDI on the PC host, but if I create the VDI on the PC host, using it on the Mac host should be OK?

That would be the general idea, yes. The idea is to keep the virtual hardware as similar as possible on all hosts so that the guest OS sees no significant change as you move from host to host. So, that will indeed mean not using a feature unless it's available on all hosts.

russff wrote:

mpack wrote:it's only the guest OS which might care.

That makes sense, I was thinking more about VBox than the guest. To keep the settings to the "weakest link", that would mean creating the VDI on the weakest link? Some settings like VT-X are available on my Mac host but not the PC host, so if I create the VDI on the Mac, this setting gets turned on by default and then causes problems if I use the VDI on the PC host, but if I create the VDI on the PC host, using it on the Mac host should be OK?

If the PC can't use VT-x/AMD-V, but the Mac can, then you of course turn it off on the Mac in the VM settings. That's how you set things up on both systems. Put the screens next to each other, compared screen by screen and set everything on the Mac the same as they are on the PC. The PC properly doesn't have the VT-x/AMD-V tab, so that's an easy guess, disable everything on the Mac for that.