I recently bought a 32 core monster-server intended to be used for virtualization. The machine is equipped with 2 x 16 core AMD bulldozer processors.
I have been using Virtualbox for several years and it’s always been a very pleasant experience, up till now that is. I have installed two guest in this machine and experiencing terrible performance, frankly it performs like sh*t.
Both VMs have been given 2 cores and 4 GB memory and can easily sink them both. An easy task such as scp to one of the guests on a Gbit network makes the machine consume more or less both cores given. The throughput seldom goes beyond 3Mb/sec. Repeating the same operation but to the host gives me a more expected throughput of about 30Mb/sec. I have used several different sources when performing these scp-tests.
I must have tested to change more or less every parameter available on those guest and nothing seem to help. I have tested both the OSE and the closed source versions as well as at least two different releases of the closed source version.
I’m starting to believe there is some sort of compability issue and therefore very interested to hear if someone with a similar setup either share my experience or managed to get this working.
> Look at there two tests. Same config but I waited about 10 min between
> the two tests, somethings fishy…
This is just a guess and I’m sorry I can’t be more specific…
I seem to remember reading somewhere that VM’s can take a severe
performance hit if TCP checksums and other functions are offloaded to the
network adapter. If that is your problem and you can disable those
functions on the adapter, it may help.
On Fri, 30 Dec 2011 18:16:02 +0000, please try again wrote:
>
> Code:
> --------------------
> /sbin/ethtool -K eth0 tso off
> --------------------
>
> Kevin,
> Is that what you mean?
Yes, I think that is it. It would have taken me quite a while to dig it
up. I haven’t had to use it myself. If I remember correctly, it needs to
be done for each VM.
Hi guys, thanks a lot for your efforts, I really appreciate it.
The Nics in the host are Broadcom Netextream II adapters (bnx2) with (at least) iscsi offload. So that might definitely be something worth trying.
However, now then concentrating some of my tests against the host I also found abnormal differences between same tests. And the throughput between other, much older physical machines on the same net have much higher throughput. I think I have some issue in this new machine either with a broken driver or bad cable or something. I guess that needs to resolved first, maybe that is “the” issue…
On the other hand, kvm is not very complicated to set up and would probably be happy with 32 cores (although I don’t have such a monster, so I don’t know). You can easily create a vm with one of the scripts I wrote (vm-create) in a package called vmscripts available in my repo. Btw, the package also includes vboxlive, that lets you create and run most Linux distros live systems on the fly in diskless vms (maybe it would help exclude disk I/O problems in your tests).
If you run both, VirtualBox an kvm on your 32 cores server, you could certainly tell use which one performs better on this monster (it will be a great info in this subforum, I guess), and you would also find out if the issue you’re having is related to VirtualBox (I doubt it though).
If you run both, VirtualBox an kvm on your 32 cores server, you could certainly tell use which one performs better on this monster (it will be a great info in this subforum, I guess), and you would also find out if the issue you’re having is related to VirtualBox (I doubt it though).
I actually did install kvm some time ago sharing your though, to create a reference. Not read your links yet, but what I failed to find then was how-to administrative kvm in a headless environment, you know if there is some virtual console such a vnc or similar ? No X installed on the server.
Of course! It’s called virt-manager. Look at the first link in my previous post. You connect to the server from anywhere and administrate the vms, start, shut down, open a vnc viewer (you can start virt-viewer from virt-manager). It’s a bummer that vbox is not implemented in virt-manager, because libvirt (not any version) is able to manage VirtualBox vms as well. So you can administrate them from the libvirt shell (virsh).