In this section, we cover discussion of Fedora virtualization technologies on the @fedora-virt and @fedora-xen-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, 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.
"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
# 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.
Xen Domain0 Kernels
Until support for pv_ops is added to the upstream kernel (F13?), it takes some twiddling to host Xen guests on Fedora. Even then it isn't recommended for anything more than experimentation at this time. More adventurous users are reporting some success with experimental kernels and running a Xen dom0.