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I have 2 virtual machines I'm trying to convert from VirtualBox to VMWare server. I exported the hard drives using the command

VBoxManage clonehd [uuid] OpenBSD.vmdk -format VMDK

This produced vmdk files that I put in the storage folder of VMWare server. I configured machines with the same parameters, but get the following error on boot:

DetailsVMware Server unrecoverable error: (vmx)
ASSERT d:/build/ob/bora-203138/bora/devices/disk/disk.c:3868 bugNr=21838
A log file is available in "D:\vmachines\vmware\OpenBSD\vmware.log".  A core file is available in "D:\vmachines\vmware\OpenBSD\vmware-vmx-5852.dmp".  Please request support and include the contents of the log file and core file.  
To collect data to submit to VMware support, select Help > About and click "Collect Support Data". You can also run the "vm-support" script in the Workstation folder directly.
We will respond on the basis of your support entitlement.

I am having similar issues with a Ubuntu VM. Both are headless machines with pretty simple hardware configurations.

Log file available at

Any ideas?

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Any chance you can paste a copy of that vmware.log file? May give some clues! – William Hilsum Sep 18 '10 at 22:15
It was over 600 lines, so I put it on pastebin and linked to it – Tim Hoolihan Sep 18 '10 at 23:24

All I can say is it looks like it isn't a valid VMDK file and it is causing VMware Server to crash.

After looking at that log file and a bit of creative Googling, I found other people who have come up with the same problem - I cannot find a solution and it looks like this is a bug with VirtualBox.

I would personally try, if you have a machine with VMWare Workstation, using the Import tool and directly trying to convert the entire Virtual Box Virtual Machine.

Sorry I couldn't be more help.

share|improve this answer
This is the answer. I had the exact same problem. Converting with VBoxManage is causing some troubles and vmware server doens't like the converted machine. I converted the machine using vmware converter and it worked. – Ergec May 30 '13 at 9:08

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