why 2GB is the max size of memory for VM using EFI?

[takwing]

If I allocate more than 2GB of memory to my Mac OS X VM with the EFI option enabled, the VM cannot start up (the virtualbox logo does not even show up).

Any reason for this? What I can confirm is that this happens for both VB3.2.4 and VB3.2.2.... but I am not sure about VB3.2.0.

Is this a known limitation? or is it a bug?

[Technologov]

1. Is your host OS kernel 64-bit ?
2. Can you start other (non-Mac) VMs with more RAM on your host kernel?

-Technologov

[takwing]

my host is win7 64-bit.

I can allocate more than 2GB RAM to start other nonMac VMs.

[Technologov]

You can open bug about it, although non-Mac hosts not supported for Mac guests, so you may get INVALID status on the bug report.

Ideally would be to ask someone to reproduce it on Mac OS X host.

[baf]

MacBook Pro with 4GB ram running SnowLeopard. Just tested to give a SnowLeopard guest 2404MB Ram without any problems.
So its something else....

[nike]

EFI doesn't make any special assumptions about guest RAM size. Was able to start and use 64-bit EFI VM with 4G RAM on Linux host.

[wyrdR]

If I allocate more than 2GB of memory to my Mac OS X VM with the EFI option enabled, the VM cannot start up (the virtualbox logo does not even show up).

Any reason for this? What I can confirm is that this happens for both VB3.2.4 and VB3.2.2.... but I am not sure about VB3.2.0.

Is this a known limitation? or is it a bug?

Similar issue:

Snow Leopard on Snow Leopard - 64Bit issues/2GB RAM limit?

I cannot boot Mac OS X Server 10.6.x with Mac OS X Server (64 bit) selected, just Mac OS X Server. I can't use more than 2GB.

PS - Submitted bug #7028

PPS - Didn't need to. It was already submitted in ticket # 7002

[Technologov]

Try the new 3.2.6 BETA, and tell us results.

[wyrdR]

Although booting with Mac OS X Server (64 bit) now works, but using more than 2GB RAM still fails for me.

[wyrdR]

If I allocate more than 2GB of memory to my Mac OS X VM with the EFI option enabled, the VM cannot start up (the virtualbox logo does not even show up).

Any reason for this? What I can confirm is that this happens for both VB3.2.4 and VB3.2.2.... but I am not sure about VB3.2.0.

Is this a known limitation? or is it a bug?

Just out of curiosity, how much Video Memory is assigned to the Guest? In 3.2.6 Beta 1 at least, I find that reducing Video Memory to 64MB or less seems to at least let the EFI boot screen start up.

i.e. If you want more than 2048 MB Memory, try reducing Video Memory to 64 MB or less.

Back with 3.2.4:
64Bit is still shot; In 32Bit with only 64MB Video Memory, I could raise the VM's memory to 3GB and still boot in EFI. I couldn't go higher on this machine, but I'll try with the server at work and let you know.

[takwing]

wyrdR,

I confirmed that with the VM's video memory set to 64MB, the VM can be started and SL can boot up normally by using 3GB of memopry.

The correct amount of memory is also shown in SL.

Thanks!


This should be a valuable information for the team to debug/investigate this issue.

[Technologov]

Please discuss this problem on the BETA forum. This will increase your chances to get fix in few days.

[wyrdR]

Please discuss this problem on the BETA forum. This will increase your chances to get fix in few days.

Thanks Technologov.

We started off talking about problems with release versions – I was just confirming that the same problem exists in the beta as well and that the work around (in both release and beta versions) is to limit the Video Memory to 64MB.

I'm hoping the existence of Ticket #7002 means it's well on the way to being fixed.