* slow responsiveness of kvm guests
@ 2009-07-31 14:15 Kai Zimmer
2009-08-03 12:40 ` Avi Kivity
0 siblings, 1 reply; 2+ messages in thread
From: Kai Zimmer @ 2009-07-31 14:15 UTC (permalink / raw)
To: kvm
Hi,
i have three guests running via qemu-kvm. All three are webservers using apache2/django and mysql. System load is very low on all guests and the host, too. Guest 1 reaction times (web server, ssh) are fine as long as no other guest is getting busy. When i ssh to guest 2 it takes 5-15 seconds until i get a login. When i run top or htop on one of the guests the other guests don't react for 5 seconds (webservers or typing in ssh shell). My colleagues already try to convince me to use xen instead...
already
- disabled apm and acpi in the guests
- turned Hyperthreading off
- tried different i/o schedulers: cfq vs. deadline. Result is the same.
- nailed down guest process via taskset to separate cpu cores
host is
OpenSuSe 11.1 x86_64
kvm-78-6.5.1
2xXeon 5550 Nehalem (Quadcores, Speedstep-enabled)
48 GB RAM
1 GB Ethernet as tap interface
all three guests are
Debian 5.0 x86_64
two virtual cpus
4GB RAM (hugepage-backed)
started via
qemu-kvm -hda xyz.qcow2 -daemonize -net nic,model=virtio -net tap -k de -m 3584 -smp 2 -mem-path /hugepages -vnc :2
Any ideas what goes wrong here?
Kai
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: slow responsiveness of kvm guests
2009-07-31 14:15 slow responsiveness of kvm guests Kai Zimmer
@ 2009-08-03 12:40 ` Avi Kivity
0 siblings, 0 replies; 2+ messages in thread
From: Avi Kivity @ 2009-08-03 12:40 UTC (permalink / raw)
To: kai; +Cc: kvm
On 07/31/2009 05:15 PM, Kai Zimmer wrote:
> qemu-kvm -hda xyz.qcow2 -daemonize -net nic,model=virtio -net tap -k de -m 3584 -smp 2 -mem-path /hugepages -vnc :2
>
> Any ideas what goes wrong here?
>
All three guests have the same MAC address, so when one talks, you can't
hear the others.
Use -net nic,model=virtio,macaddr=00:11:22:33:44:0{1,2,3} (different
addresses for different guests).
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 2+ messages in thread
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2009-07-31 14:15 slow responsiveness of kvm guests Kai Zimmer
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