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I am using VirtualBox version 4.1.12_Ubuntur77245. Following is a screenshot of the command htop. Why does virtualbox spawn multiple processes for a single VM?

Enter image description here

mihirj
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1 Answers1

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Those aren't processes, they're threads. As indicated by the graph, all but the top one are threads spawned by the main process 3164. (Each thread also gets its own PID in Linux.)

You can press H in htop to collapse or expand process threads.

Michael Hampton
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  • I don't know this for sure, but I would expect there to be at least one host thread per virtual CPU, and depending on how deep the paravirtualization goes, perhaps as many as one host thread per thread executing within the virtual machine. – zwol Feb 01 '15 at 02:01
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    @zwol I'd expect a thread per vCPU and threads for virtual hardware devices. – Michael Hampton Feb 01 '15 at 02:19
  • Don't forget about threads for other stuff like Clipboard sharing and Drag & Drop. –  Feb 01 '15 at 06:29