There are only 2 serial ports available per virtual machine

[aminm]

It seems that VirtualBox cannot support more than 2 serial ports per virtual machine. This limitation severly hampers the usefulness of VirtualBox for my applications. I run virtualized fax servers that are portable across OSs and connect to external modems through mapped serial ports. For a typical 4 or 8 line fax board, this means I cannot scale the application to fully utilize the available hardware. As far as I know only VMWare supports unlimited serial ports per VM among the competition.

[BusyBoy]

Hi Aminm

Did you ever find a solution for this issue with virtualbox

"It seems that VirtualBox cannot support more than 2 serial ports per virtual machine. This limitation severly hampers the usefulness of VirtualBox for my applications. I run virtualized fax servers that are portable across OSs and connect to external modems through mapped serial ports. For a typical 4 or 8 line fax board, this means I cannot scale the application to fully utilize the available hardware. As far as I know only VMWare supports unlimited serial ports per VM among the competition. "

[Netika]

Hello,

has anyone found any workaround ? I'm using VirtualBox as fax server too, and the only way I found is to install a second virtual machine to connect additionnal modems...

I have modems and can help for testing.

[Maxim-Allen Mukhin]

Hello, I have stumbled at this limitation in version 5.0.12 (r104815). Likewise need more than 2 serial ports. Using serial ports for microcontroller development.

[frank]

Fix is part of VBox 5.0.16.

[AmZaf]

The limitation is increased from 2 to 4 ports. I wish it would have increased to 16 to bring it in line with VMware virtual machine spec.