Add network interface for KVM instance in GPL version

Hi all,

I installed Cloudmin GPL version on Ubuntu 11.04 for testing purposes. But I can not find any possibility to add more than one network interface to KVM instance (linux or win).
I read documentation, that navigated me to System Configuration category and Network Interfaces, but nothing like that is in my Cloudmin web.

It is possible to add virtual or real network interface to the virtual KVM machine in GPL version?


Yes, this is possible - you can go to System Configuration -> Network Interfaces, and click “Add a real interface”, typically eth1 . If your host system has multiple bridges, you can select the bridge like br1 that the new interface should be connected to on the host - this is most useful if br1 is then connected to another LAN on the host, like eth1 .

okinobk, sorry to hijack your topic:-) But I am wondering what is your write performance in KVM? For example if you run the following command (which writes a 260MB file test)

dd if=/dev/zero of=test bs=16k count=16k conv=fdatasync

Thank you Jamie, but your method is the same like in the manual. I Installed clear Ubuntu server 11.04 (host) with static ip network settings for eth0. Then I installed Cloudmin GPL with KVM by script on webmin website. As guest is Ubuntu server 11.04, status in Cloudmin is Alive.

But no menu like Network Interfaces is showed in left Cloudmin menu. In System Configuration (in host) is only Reverse Addresses. When I used search function to find ‘network’, I found this items in search list, but there was no link.

My Cloudmin version is 5.4.kvm GPL, Webmin version 1.550.

I test your command. Here is result from guest:

okinobk@ubuntuvirt:~$ dd if=/dev/zero of=test bs=16k count=16k conv=fdatasync
16384+0 records in
16384+0 records out
268435456 bytes (268 MB) copied, 16.6495 s, 16.1 MB/s

My testing configuration:
INTEL Core 2 Quad Q6600
DDR2 4GB 800Mhz
2x HDD 320GB 7200 SATA2 16M cache (with software raid1, mount to host, guest systems)
USB flash drive KINGSTON DataTraveller 410 (this drive is used for host system)

Host: Ubuntu server 11.04 (clear system with Cloudmin GPL with KVM)
Guest: Ubuntu server 11.04 (clear system)

Do you think these performance in KVM can be better?

Now I tested it in host system (installed on USB flash key).

okinobk@ubuntuhost:/virt$ dd if=/dev/zero of=test bs=16k count=16k conv=fdatasync
16384+0 records in
16384+0 records out
268435456 bytes (268 MB) copied, 2.69679 s, 99.5 MB/s

This is huge difference. Is it normal?

I got it :slight_smile:

I installed webmin to guest ubuntu and setup SSH auth in cloudmin guest settings. Then restart guest and now ti show me network menu for guest.

So now, my question is if it is possible for windows guest.

Currently it is not possible to add an extra interface to a Windows VM , as Cloudmin doesn’t know how to setup networking on the VM as it does for Linux.

Let’s continue the discussion in

You can see that I had essentially identically results (on less powerful hardware). There seems to be roughly a 1000% performance hit with KVM compared to OpenVZ/host.