2 Replies Latest reply on Oct 19, 2013 4:07 AM by onepablo

    Why is VMNAT.EXE eating up my cpu?

    zrlKyMJYR8 Lurker

      I have VMwarePlayer 5.0.2 installed on Win 7 SP1, fully updated.


      I have a Linux Mint KDE 13 (now 14, see below) installed as a guest O/S.


      I see the following behaviour: after a period of browsing VMnat.exe use goes up to 25% on the host CPU (Intel 5 dual core with multi threading, 2nd gen).  Even after I boot off the guest Mint the vmnat.exe process stays at 25% with several mintues, until I kill it (It doesn't seem to want to, say, finish some work and go away).


      I completely reinstalled Win 7, VMwarePlayer 5.0.2 and installed Mint KDE 14 instead of Mint KDE 13 as guest.  Makes no difference.  (I have declared these O/S's as Ubuntu to the player.)


      I thought that maybe I could solve the problem by giving the guest only one core (of the 4 logical cores) but that only brought the cpu usage up to 45%.  Even if I close the vmware player, the vmnat.exe process continues to eat up 25% (or 45%) of cpu.


      I find that I can kill the vmnat.exe process in the host when it has this heavy cpu usage without even booting off the guest.  After a bit, the guest will continue to work and access the Internet without vmnat.exe cpu usage showing up again.  But I would rather not have to keep track of cpu usage of vmnat.exe manually.  I would like to fix this issue.


      I saw through googling that running vmnetui.dll as an app using rundll32.exe in an administrator acct would allow me to reset the network config--which some people seem to think might solve the problem, or at least a related problem.  However, I can't get rundll32 to run vmnetui.  I get a message, 'The operating system cannot run %1'.  I added the VMware path to the path environment variable and double-checked but it makes no difference.  This is before and after win7 system reinstallation.


      Now I really don't need to fiddle with the network (the setting is NAT to share the host's IP address).  The connection is a 2.5 MByte wireless connection which doesn't seem to present any problems.  My only issue is the detected heavy cpu usage by vmnat.exe even when the guest is idling or shut down.  My only interest in vmnetui is as a possible means to fix vmnat.exe so that it doesn't have this heavy cpu usage.


      Would appreciate some suggestions how to solve the high CPU usage problem.  Thanks very much.


      Message was edited by: zrlKyMJYR8 to improve clarity and remove typos.

        • 1. Re: Why is VMNAT.EXE eating up my cpu?
          kingofbytes01 Lurker

          I have the same issue.  It randomly spikes and stays spiked chewing up one of my procs.  I can always tell because the fan on my laptop kicks up a bit.  I then go in and kill vmnat.exe with task manager, but that doesn't solve the problem - it just temporarily fixes the issue.


          Some others have said to "reset" the network stack - this is a clugy workaround - not a solution and I'm not convinced it does anything anyway, since killing in task manager achieves the same result without the kabuki theater fix.


          btw, this happened in all versions of Workstation 8 and 9 (I'm currently using 9 and have no plans to move to 10).  I don't think it was an issue in Workstation 7.  Help!

          • 2. Re: Why is VMNAT.EXE eating up my cpu?
            onepablo Lurker

            Same happening to me; Win 7 hosting Mint 15.  I am using Cisco VPN on the host (Windows) machine.  But yep, it's sat there at 25% making the fan whiiiiiir worryingly.