virtualbox.org

I am finding that I am unable to run multiple guests on my new Ubuntu 8.04 AMD64 System.
I have been running Virtualbox (since v1.4) on my Dell Notebook using PCLinuxOS 2007 as the host OS, with as many as 4 guests, without any problems. Has anyone successfully run multiple guests on Ubuntu 8.04 AMD64? Just wondering if I will need to drop back to a 32 bit OS. I don't think this is a hardware issue because it doesn't crash the host OS only the Guest systems.

Okay, it may have been hardware related after all. After disabling VT-x/AMD-V in all virtual machines everything seems to work fine with multiple virtual machines running. As I type this I am also running two windows XP and one Windows 2000 instance and all seem to be working fine. I have seen several posts in other forums related to issues with the AMD Phenom 9500 processor, and wouldn't you know it that is what I'm running. This issue seems to be resolved.

I am running VirtualBox 1.6.2 on Kubuntu 8.04/AMD 64 with AMD-V enabled. I have no problems running multiple hosts. I got a AMD Athlon(tm) 64 X2 Dual Core Processor 3800+ cpu. But as you say, I think I have seen some post about problems with the Phenom cpu.

With AMD-V disabled I have been running flawlessly with multiple guests, up to 4 at a time, a mixture of both Microsoft and Linux. All guests and the host remain stable . I think I will just be content to leave AMD-V disabled at this point. Based on some of the complaints I have read about the AMD Phenom 9500 cpu I am rather pleased that it is not hanging under heavy loads.