virtualbox.org

I installed a Windows 2k guest on an Ubuntu 9.04 64-bit host using the latest version of Virtualbox. Everything seems to be working great except for one particular program that locks up the Win2k. This program appears to execute a series of 16-bit dos programs that communicate with each other via text files. Could this (16-bit code) be the cause of the lockup? The program runs fine on Win2k that is running directly on a a computer.

Tom

I've had that too but it was bad programming related, the real server sometimes hung and no one could figure out why until it got virtualized and hung everyday, debugging the VM revealed the problem. A real machine has very limited but real potentional to recover from basic faults that a VM does not which easely explains the difference.

When the program locks up Win2k there are 8-10 copies of NTVDM.EXE running (or trying to run). I am mostly ignorant about such things, but these appear to be the virtual dos machines used to run the 16-bit code. I have also read that 64-bit computers can't run 16-bit code (for reasons I don't understand). This all sounds nice, but I have a Vista 64-bit host OS running a Win2k guest (using MS Virtual PC) and the problematic program runs fine there.

VirtualBox emulates 16-bit instructions when needed, and it should do it on both host operating systems equally well...

Is the w2k VM running with vt-x enabled? run it without.

Nope. Still locks up. I am going to see if I can find a small 16-bit program that I can use to reproduce the problem.

Tom

Or run a old debugger like codeview.