Serial Modems and ESX 3.5

[jaredm77]

I have been through Hell and back trying to find a solution to this problem to no avail, so hopefully this place will be the last bastion for my sanity....

I recently setup a Dell 2950 server running ESX Server 3.5 to replace 4 physical servers that transmit medical data. Each of the physical servers has it's own U.S. Robotics 56K serial modem and phone line. At night, all 4 modems are transmitting at one time. The 2950 has 1 serial port on the server itself, so I added two SIIG PCI cards, one with 1 x RS232 port and another with 2 x RS232 ports. Upon migrating the old servers over, I am only able to assign them ttyS0 or ttyS1, and have no option for any other ports. One of the connections on the 2-Port PCI card works in one of the VM's to transmit data, but none of the other ports will work with any other vm. I called VMware support and they told me it wasn't possible for me to do what I wanted because they don't support PCI serial cards. Is there any way to set this up to work? Is there some alternative that will allow it to function as described above? I am relatively new to the VMware universe, recently being converted from Microsoft Virtual Server 2005. We do have a VirtualCenter server setup if that helps at all with configuration.

Thanks!

[kjb007]

It is difficult, if not impossible to "share" peripherals between esx hosts and the vm's, because the vm hardware is not 1:1 with esx hardware. That being said, when you say you have one of the vm's able to transmit. Is it connected to S0 or S1? When you use an alternate VM, are you trying to connect to the same port?

Try typing 'setserial /dev/ttyS*' in your service console, and see if you can see your port types listed in the output for ttyS0-4

-KjB

[Ken_Cline · Accepted solution]

VMware support told you the truth. Remember, the service console is a VM that can see only what the vmkernel allows it to see. Since the vmkernel doesn't understand the PCI add-in card, it will not pass it through to the service console. Your best bet to accomplish what you want is to use a "serial over IP" solution like the following:

- Avocent ESP Serial Hub

- Perle Serial-Ethernet Adapters

- Digi Serial Servers

- Google Search

Good luck!

Ken Cline

Technical Director, Virtualization

Wells Landers

VMware Communities User Moderator

[jaredm77]

I am looking at the Avocent ESP-4 MI device and just so I'm clear before ordering: I will hook the device up to my network with the modems attached to it, then install the driver software inside each of the virtual machines, directing them to one of the ports on the Avocent device where they will see the attached modem?

If so, sounds good to me!

[Ken_Cline]

Yep...that's the idea. You'll basically install a device driver inside the guest OS in the VM that will appear to an application to be a serial port, but in fact, the device driver will redirect all I/O operations across your IP network to the remote device (i.e. the Avocent) which will communicate with the modem. It's slick, and it works well. Another neat thing is that, since the modem is "network attached", VMotion and DRS will work with your VM...if you connect the modem directly to your host, those features won't work.

Ken Cline

Technical Director, Virtualization

Wells Landers

VMware Communities User Moderator

[jaredm77]

I purchased the Avocent ESP-4 MI and have it hooked up to one of the modems. I installed the device driver software on my Windows 2000 Advanced Server VM and proceeded to add the modem. It comes back as an Unknown Modem and will not dial out. I can query the modem, but cannot actually use. The modem is a U.S. Robotics Courier V.Everything External. Any ideas?

[Ken_Cline]

I'd suggest a call to Avocent - they should be able to help you out very quickly.

Ken Cline

Technical Director, Virtualization

Wells Landers

VMware Communities User Moderator

[adecker]

I have about the same setup and had about the same problem. When I auto configured the initialization string of the modem it came back with "E!N0Q0V1X4&C1&D2&MO&Q0\g0\j1\n0%C0" and the modem would dial out with this setting, but then error out when communicating. I spent half a day playing with the initialization string until I came up with "F1&K0&MO" which has worked fine since. Don't know if that is your issue but worth a try.

[dtodd1]

I am attempting a similar process, and was leaning towards the DIGI Connect SP product .

http://www.digi.com/products/serialservers/digiconnectsp.jsp

Has anyone tried this one?

Doug

[Craigie123]

Guys

I have noticed that this thread happened a while ago i have a few questions?

I have a simular requirement with vSphere 4.0 did this soultion work? Will it work with 4.0?? Has anyone else had experience of this?

I have remote computers that connect to a central office via modems to send and receive updates to and from the central server (all physical computers).

I am setting up a VMware test environment to replicate this setup. I think that i am going to have to setup the remote computer as a phsical pc and connect it to the VM's that will connect to the modem this side through ethernet.    

Any Ideas of the equipemnt that i need to use that works?

Thanks in advance

Craig