Com Ports not working on Virtual Server Guest OS
I have a Win2K3 guest OS running on a Win2K3 host using Virtual Server 2005. The guest is running Net Satisfaxion 7.2, connecting to a USR fax modem on Com1 of the host. This configuration has worked reliably for over 2 years. About two weeks ago the fax software stopped working. It is no longer able to connect to the Com port. I'm getting the following error in the Virtual Server logs on the host when I try to launch the Net Satisfaxion software:
"There was an error trying to open the following port "COM4" on your host machine. Before this port can be connected to "appsvm", you must verify that a device is attached to the port, and that it is not being used by another process."
I have tried everything I can find to resolve this issue with no luck. The original configuration pointed to Com1. I have installed a 2-port serial board in case the integrated serial port was bad. No change.
One issue is that the host auto-detects the modem as soon as it is connected to the serial port. I have tried using generic drivers instead of the USR drivers with no luck. Over the weekend I disabled the drivers on the host. This allowed the guest to start using the modem, although no fax drivers were installed on the guest. Unfortunately this did not last. Within an hour the error message was back.
I've gone through every KB and blog I can find with no luck. Any help is appreciated.
"There was an error trying to open the following port "COM4" on your host machine. Before this port can be connected to "appsvm", you must verify that a device is attached to the port, and that it is not being used by another process."
I have tried everything I can find to resolve this issue with no luck. The original configuration pointed to Com1. I have installed a 2-port serial board in case the integrated serial port was bad. No change.
One issue is that the host auto-detects the modem as soon as it is connected to the serial port. I have tried using generic drivers instead of the USR drivers with no luck. Over the weekend I disabled the drivers on the host. This allowed the guest to start using the modem, although no fax drivers were installed on the guest. Unfortunately this did not last. Within an hour the error message was back.
I've gone through every KB and blog I can find with no luck. Any help is appreciated.
Can you check the comport under the Device Manager to see what currently is occupying com1. Looks like there is a conflict of comport; 2 devices using the same port. You can always change the comport on your USR modem to use a different port if that is an option.
ASKER
Device Manager shows nothing on any of the ports until I connect one of the modems. With the new serial board I now have three different ports to choose from. They all result in the same error.
Can you change the comport on the USR modem to use Com4 instead. Just to test and see if your application is now using com4.
ASKER
I've attached modems to both new ports (Com3 and Com4.) The host sees both modems. I've changed the port mappings for the VM from one port to the other and back again multiple times. Sometimes it works for a few minutes, sometimes the error occurs immediately after launching the fax software. Either way the error occurrs.
Have you attempted to contact the fax software vendor? Is there a configuration within the fax software which will allow you to change the port?
ASKER
I have not contacted the software vendor. This configuration worked for over 2 years, so I'm confident that the software settings are correct. (A detailed Google search found nothing regarding Net Satisfaxion and VM's.) Because the error is being generated within Virtual Server, I'm assuming the problem is there or in the hardware.
Unfortunately I am not familiar with the Net Satisfaxtion software so I can't really comments on how they functions. However, from what you have given us so far, I am pointing it to the software problem not the hardware problem as you had attached your modem to a different port and the problem still exists.
Have you made any change lately on any server? Have you done any Windows Update lately?
Have you made any change lately on any server? Have you done any Windows Update lately?
ASKER
No changes to the server until the new serial board was installed after the problem started. Windows Updates are applied regularly but I don't have any direct correlation. No changes were made to the VM. Again, the error is occuring in Virtual Server.
ASKER
Anyone else?
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ASKER
Nothing in the MS documentation or KB has any indication that the SCVMM client would interfer with the com ports!