After "ethtool -K eth0 gro off" ssh into the machine (either the host or the
VM's) became unreliable--very slow, with frequent dropped connections. However, this
was while using sshuttle.
Ross
________________________________________
From: Boylan, Ross
Sent: Friday, March 20, 2015 1:12 PM
To: libvirt-users(a)redhat.com
Subject: RE: [libvirt-users] getting oriented/networking [some success]
I seem to have run into
https://bugzilla.redhat.com/show_bug.cgi?id=855640, because when I
tried the fix/work-around at the end (comment 11), ethtool -K eth0 gro off, my download
speed by speedtest went from undetectable to ~150Mb/s. However, it was not able to
connect for the upload test, and so something may still be off. Non-virtual machines can
do the upload test, so it's not just a firewall issue.
The comment refers to another source for more info, but it seems to be behind a Redhat
paywall.
Ross
________________________________________
From: Boylan, Ross
Sent: Friday, March 20, 2015 11:01 AM
To: Dominique Ramaekers; libvirt-users(a)redhat.com
Subject: RE: [libvirt-users] getting oriented/networking
Thanks very much. Unfortunately, networking is currently so slow as to be non-functional
(most operations time out). It's also erratic: I had 2 VM that were close to
identical--they were both based on the same disk image--and even when I set the networking
the same one was fine and one was very slow. Today I started up the VM that had good
networking, and it now has bad networking.
Here's one of the network specifications:
<interface type='direct'>
<mac address='52:54:00:61:7c:dc'/>
<source dev='eth1' mode='vepa'/>
<model type='virtio'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x03' function='0x0'/>
</interface>
The one that was originally fast also had a NAT network, and the one that was originally
slow was mode bridge before I changed it to vepa, which didn't help.
The drivers came from
http://alt.fedoraproject.org/pub/alt/virtio-win/latest/images/virtio-win-... in
the 32 bit windows 7 directory of the iso (host is 64 bit, as is the emulated machine;
Windows 7 is 32 bit). I've tried shutting down, removing and reinstalling the network
adaptor, and various other things.
Ross
________________________________________
From: Dominique Ramaekers [dominique.ramaekers(a)cometal.be]
Sent: Thursday, March 19, 2015 11:21 PM
To: Boylan, Ross; libvirt-users(a)redhat.com
Subject: RE: [libvirt-users] getting oriented/networking
Dear Boyland,
In collaboration with some of this mailing list users, I had put some effort in optimising
the guest settings in function of a windows guest. The libvirt-gui doesn't include
these options. You'll have to edit the XML in virsh. This was my conclusion on
15-03-2015 but I added the hugepages tip in this list today. As for networking, I only use
or bridged or the default virtual network (NAT), so can't help you more here.
Here below, a summary of tips:
- Setting video to QXL and the display channel to Spice
<video>
<model type='qxl' ram='65536' vram='65536'
heads='1'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x02' function='0x0'/>
</video>
<channel type='spicevmc'>
<target type='virtio' name='com.redhat.spice.0'/>
<address type='virtio-serial' controller='0'
bus='0' port='1'/>
</channel>
- Using HyperV enlightenemt timer
<features>
<hyperv>
<relaxed state='on'/>
<vapic state='on'/>
<spinlocks state='on' retries='8191'/>
</hyperv>
<features/>
<clock ...>
<timer name='hypervclock' present='yes'/>
</clock>
- Delete the tablet entry in the input section or set the USB-bus to USB2 or USB3
- Use hugepages
<memoryBacking>
<hugepages/>
</memoryBacking>
Again thanks Daniel and Andrey.
Hope this helps.
Grts, Dominique.
-----Oorspronkelijk bericht-----
Van: Boylan, Ross [mailto:Ross.Boylan@ucsf.edu]
Verzonden: vrijdag 20 maart 2015 1:52
Aan: libvirt-users(a)redhat.com
Onderwerp: [libvirt-users] getting oriented/networking
I've been using virt-manager and kvm with a disk image (as in the raw bits) from a
physical windows 7 machine. Initial performance was dreadful, but improved as I switched
to virtio and spice. I've been running linux VM's somewhat longer (much longer if
you count kvm without libvirt).
There are lots of choices exposed by virt-manager. How do I find out what the choices
mean, and which are good ones? This was true for the video (resolved by following
instructions for spice, though I still wonder what the other settings are for), disks and
the network.
In particular, I have a choice of lots of interfaces for my network; I picked eth1:macvtap
because I wanted to bridge eth1. But there is a "Source Mode" which I left at
VEPA, even though Bridged was another choice. But the bridge would already seem implicit
in picking a source device of eth1:macvtap. I don't know what "source mode"
means. The choices in the GUI seem like some of the options listed under forward on
http://libvirt.org/formatnetwork.html; is that a good place to look for clarification.
I started a 2nd VM that also used eth1:macvtap (with virtio) and it had almost no network
throughput. So maybe I should use some other method? I notice the network manager
connection gui allows creation of bridges on the network; should I be using that?
I have been reading documentation, but I haven't found either a task-oriented
discussion ("to get a windows machine working well, use these options" or
"follow these steps") or an easy way to go from the choices in the GUI to a
discussion of their meaning.
Thanks for any help you can offer.
Ross Boylan
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