Oracle VM VirtualBox is capable of producing its own core files for extensive debugging when things go wrong. Currently this is only available on Oracle Solaris hosts.

The Oracle VM VirtualBox CoreDumper can be enabled using the following command:

$ VBoxManage setextradata VM-name VBoxInternal2/CoreDumpEnabled 1

You can specify which directory to use for core dumps with this command, as follows:

$ VBoxManage setextradata VM-name VBoxInternal2/CoreDumpDir path-to-directory

Make sure the directory you specify is on a volume with sufficient free space and that the Oracle VM VirtualBox process has sufficient permissions to write files to this directory. If you skip this command and do not specify any core dump directory, the current directory of the Oracle VM VirtualBox executable will be used. This would most likely fail when writing cores as they are protected with root permissions. It is recommended you explicitly set a core dump directory.

You must specify when the Oracle VM VirtualBox CoreDumper should be triggered. This is done using the following commands:

$ VBoxManage setextradata VM-name VBoxInternal2/CoreDumpReplaceSystemDump 1
$ VBoxManage setextradata VM-name VBoxInternal2/CoreDumpLive 1

At least one of the above two commands will have to be provided if you have enabled the Oracle VM VirtualBox CoreDumper.

Setting CoreDumpReplaceSystemDump sets up the VM to override the host's core dumping mechanism and in the event of any crash only the Oracle VM VirtualBox CoreDumper would produce the core file.

Setting CoreDumpLive sets up the VM to produce cores whenever the VM process receives a SIGUSR2 signal. After producing the core file, the VM will not be terminated and will continue to run. You can thus take cores of the VM process using the following command:

$ kill -s SIGUSR2 VM-process-id

The Oracle VM VirtualBox CoreDumper creates core files of the form core.vb.process-name.process-ID such as core.vb.VBoxHeadless.11321.