Changing NIC Speed on Host

[zekebashi]

Hello,

I am new to Virtualization and to VirtualBox. I was provided with a VM from our vendor to import into a Win2008 R2 Host server. Everything seems to be working just fine. I came to find out that the NIC on host server is setup to 100Mbps and want to change it to 1Gbps. My question is, once I have changed the host's NIC to a Gig, do I need to do anything on the VM? What is the proper way of accomplishing this?

Much appreciated.

Best, ~zK

[Perryg]

It depends on the guest and what it uses. You don't say.

[zekebashi]

Thanks for the reply. The guest is a linux.

Thanks, ~sK

[Perryg]

OK that narrows it down to about 250 different distros.

Depending on the distro and the version and the kernel it may be that you will be able to use the VirtIO paravirtualized network adapter and if so nothing is faster.

[zekebashi]

Here is the #uname -a
Linux 2.6.18-274.3.1.e15 .... x86_64 x86_64 GNU/Linux.

So, are you saying that if I upgraded the host's NIC to a Gig, it won't affect the speed of the VM's NIC and it would remain at a 100Mbps?

Thanks, ~sK

[Perryg]

No that's not what I said at all. What I said is if you can in fact use the VirtIO drivers you can not get a faster speed. It actually supports 1GB at the moment and I am sure it could be made to go faster if and when the time comes.

What does cat /etc/issue in a terminal show?

[zekebashi]

Output of cat /etc/issue is as follows:

CentOS release 5.7(Final)
Kernel \r on an \m

Best, ~sK

[Perryg]

Should work. You may need to ask the Centos people how to tune for performance.

[mpack]

@zekebashi: just for clarification, the networking card used in the VM is not physical and hence has no physical bandwidth constraints. Yes, it will report some arbitrary number when queried, but actual bandwidth is the same as your host. Using VirtIO-net ensures that the simulation is as efficient as possible, hence you get as close as possible to the bandwidth of the host.