i am running vmware 4.5.3 on fedora core2, i just installed windows 2000 in there, it was fine for couple of hours, until i restart vmware, now i got this error
could not open /dev/vmmon. no such device please make sure that the kernel module "vmmon" is loaded
any ideas ?

thank you in advance

well.. exactly what it says on the tin really... make sure vmmon is loaded.... run "modprobe vmmon" not really related to VMware....

yea, i did that, but it gives me this error
FATAL: Module /dev/vmmon not found.
i am sure that vmmon is in /dev
any ideas ?

well, i did a serach for vmmon i found there is source file in /usr/lib/vmware/modules/source for vmmon , i am trying to compile this file see if it works

well this is funny , after recompiling vommon file, i click on start button in vmware , nothing responds. is there anyway that i can same my win2000 system as a image file ? i am planning to reinstall vmware right now, but dont wanna destroy my win2000 in there

yeah the image file should be moveable in ~/.vmware by default i think.

I also use the Linux verion of Vmware. When I type "lsmod" I see that I do have a "vmmon" module loaded on my Linux host. The "lsmod" command lists all the modules that I have loaded. I see "vmnet" and "vmmon" are listed which are both Vmware modules.

I then got to wondering about what loads the modules. My understanding of how initialization is done in Linux is quite shaky, but I will go out on a limb and say how I think it roughly works. What also complicates my answer is that I am using Slackware which uses a more or less BSD style initialization while you are using Fedora which uses "System 5" style initialization. So anyway with Fedora Core Linux, Vmware probably runs this script from this location to start Vmware:

/etc/init.d/vmware

I run Vmware from Slackware 9.1 and I when I installed it I had to copy that script to a different location and rename it as this:

/etc/rc.d/rc.vmware

Depending on which Linux distro you would run one script or the other to start Vmware. In Slackware is edited my "rc.local" script to have the "rc.vmware" script started automatically. Fedora Core and most other distros would do it slightly differently. Someone else here could probably explain how to do that if necessary.

When I look inside the startup script with a text editor I see that the "vmmon" module is listed in there. So anyway you might want to try running the script with the "status" parameter to see if it is already running.

/etc/init.d/vmware status

You could also try typing this to start up Vmware:

/etc/init.d/vmware start

I believe the script was created when I originally ran the "vmware-config.pl" or possibly "vmware-config.pl --compile" while installing the Vmware.

Your Windows 2000 virtual machine should be safe and survive even if you need to re-install Vmware. I originally created most of my virtual machines back when I was using Red Hat 9. I then switched to Slackware 9.1 and was able to use my existing virtual machines. I had originally mounted them on seperate partition by the way. To find your where your virtual machines are you can type these two commands while logged in as root:

cd /
find -name *.vmdk

That should find all you "vmdk" files for you. They are most likely in a subdirectory of the vmware directory. I am Assuming that you have Windows 2000 installed on virual partitions not on a real partition. If so then, if I am not mistaken, your copy of Windows 2000 should be spread accross several of the "vmdk" files. There is a whole chapter in my Vmware manual on how to move and share virtual machines. I do not recall all the details. I think that perhaps (maybe) you FILE -> OPEN and then brows for the appropriate ".vmx" file. It should be in the same directory as the "vmdk" files. On my computer is is called "Win2000Pro.vmx. It might have a slightly different name depending on what you chose to call your Windows virtual machine.

So anyway there is still a lot of this that I do not understand very well, so perhaps someone could explain a few of the details better. I compiled my copy of Vmware from source without understanding very well what I was doing. At least it works. I also discovered that whenever I change to a newer kernel I need to rerun "vmware-config.pl --compile" again.

The use of Vmware is not supported with all distros. I do not know for sure if Vmware is compatible with Fedora Core 2. That is pretty much all that I know about the "vmnet" and "vmmon" modules and how Vmware starts and also how to move or reuse a virtual machine.

I just ran into a similar problem - had VMWare working fine, running XP, 2000, and 98 in it, and then one day I started geting the "Cannot open /dev/vmmon" error. No idea why.

Here's what makes it work again for me -

from console, type:
/etc/init.d/vmware start

Then just go into VMWare via the GUI and start your virtual machine. No idea why this works, or why suddenly things aren't initializing automatically, but I'm too sleepy to think about it any more!!