[virt-tools-list] virsh migrate --live has sever bandwidth limits?

Phil Meyer pmeyer at themeyerfarm.com
Mon Oct 17 23:18:27 UTC 2011


We are experimenting with large VMs, 4GB, live migrating from one host 
to another.

At first they were hitting our process timer, so I shut that off.

We have watched one today that started pushing 40Mb (bits) per second 
from host 1 to host 9 -- both hosts are Dell M610 blades in the same 
chassis with Gbit ports.

It is still running the migrate after 2.5 hours.  I will be leaving it 
to run over night to see what happens.

We use an intermediate host to talk to each server to initiate the live 
migrate.  ssh keys are set, and this command has always worked on 
smaller, or not busy hosts.

The KVM in question is running win2k8r2 with 2 virtual CPUs and 4GB RAM.
The host has 32GB RAM and is not very loaded at the moment.

Here is the command being executed on the intermediate host:

[root at pxe1 ~]# virsh -c qemu+ssh://root@kvm1.mydomain.net/system migrate 
--live a008881 qemu+ssh://root@kvm9.mydomain.net/system

Versions:

RHEL 6.0

libvirt-client-0.8.7-14.el6.x86_64
libvirt-debuginfo-0.8.7-14.el6.x86_64
virt-viewer-0.2.1-2.el6.x86_64
libvirt-python-0.8.7-14.el6.x86_64
libvirt-devel-0.8.7-14.el6.x86_64
python-virtinst-0.500.3-7.el6.noarch
libvirt-0.8.7-14.el6.x86_64

Is there a default 'migrate-setspeed' in the older version, and if so, 
was it ~40Kb ?

Can it be modified in this version?  There are way too many systems 
involved to do large updates at the moment.  However, a small code 
change to a couple python scripts might slide through. :)

We will be moving them to RHEL 6.1 or 6.2 in the spring.

Thanks for any pointers!




More information about the virt-tools-list mailing list