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[http://www.redhat.com/mailman/listinfo/fedora-virt fedora-virt list].
 
[http://www.redhat.com/mailman/listinfo/fedora-virt fedora-virt list].
  
====  ====
+
==== KSM Tuning Service ====
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A new feature for [[Releases/12 | Fedora 12]], Kernel Samepage Merging<ref>http://fedoraproject.org/wiki/Features/KSM</ref>,
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enables KVM guest virtual machines to share identical memory pages. This is especially useful when running multiple guests from the same or similar base operating system image. Because memory is shared, the combined memory usage of the guests is reduced. KSM works by scanning memory, looking for identical pages.
 +
 
 +
[[DanKenigsberg |Dan Kenigsberg ]]
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posted<ref>http://www.redhat.com/archives/fedora-virt/2009-September/msg00023.html</ref>
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a KSM control daemon in a
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"simple script that controls whether (and with what vigor) should ksm search duplicated memory pages."
 +
 
 +
"An unattended host running a variable number of qemu-kvm's needs to tune
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ksm automatically, since when memory is tight, it's better to spend more
 +
cpu on merging pages. In more relaxed cases, it's just a waste of time."
 +
 
 +
<references />
 +
 
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==== Host Iptables Settings for Bridged Guests ====
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[[MarkMcLoughlin|Mark McLoughlin]]
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pointed<ref>http://www.redhat.com/archives/fedora-virt/2009-September/msg00014.html</ref>
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out that the recommended<ref>http://wiki.libvirt.org/page/Networking#Fedora.2FRHEL_Bridging</ref>
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configuration for configuring iptables on the host to allow traffic to pass to
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a bridged guest to disable netfilter on the bridge altogether.
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 +
<pre>
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# cat >> /etc/sysctl.conf <<EOF
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net.bridge.bridge-nf-call-ip6tables = 0
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net.bridge.bridge-nf-call-iptables = 0
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net.bridge.bridge-nf-call-arptables = 0
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EOF
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# sysctl -p /etc/sysctl.conf
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</pre>
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 +
This "will be the default with Fedora 12."
 +
 
 
<references />
 
<references />
  

Revision as of 02:47, 7 September 2009


Virtualization

In this section, we cover discussion of Fedora virtualization technologies on the @fedora-virt, @fedora-xen-list, @libguestfs, @libvirt-list, and @virt-tools-list lists.

Contributing Writer: Dale Bewley

Fedora Virtualization List

This section contains the discussion happening on the fedora-virt list.

KSM Tuning Service

A new feature for Fedora 12, Kernel Samepage Merging[1], enables KVM guest virtual machines to share identical memory pages. This is especially useful when running multiple guests from the same or similar base operating system image. Because memory is shared, the combined memory usage of the guests is reduced. KSM works by scanning memory, looking for identical pages.

Dan Kenigsberg posted[2] a KSM control daemon in a "simple script that controls whether (and with what vigor) should ksm search duplicated memory pages."

"An unattended host running a variable number of qemu-kvm's needs to tune ksm automatically, since when memory is tight, it's better to spend more cpu on merging pages. In more relaxed cases, it's just a waste of time."

Host Iptables Settings for Bridged Guests

Mark McLoughlin pointed[1] out that the recommended[2] configuration for configuring iptables on the host to allow traffic to pass to a bridged guest to disable netfilter on the bridge altogether.

 # cat >> /etc/sysctl.conf <<EOF
 net.bridge.bridge-nf-call-ip6tables = 0
 net.bridge.bridge-nf-call-iptables = 0
 net.bridge.bridge-nf-call-arptables = 0
 EOF
 # sysctl -p /etc/sysctl.conf

This "will be the default with Fedora 12."

Fedora Xen List

This section contains the discussion happening on the fedora-xen list.


Virtualization Tools List

This section contains the discussion happening on the virt-tools-list list.


Libguestfs List

This section contains the discussion happening on the libguestfs list.


Libvirt List

This section contains the discussion happening on the libvir-list.