Virtualization
In this section, we cover discussion of Fedora virtualization technologies on the @et-mgmnt-tools-list, @fedora-xen-list, @libvirt-list and @ovirt-devel-list lists.
Contributing Writer: Dale Bewley
Enterprise Management Tools List
This section contains the discussion happening on the et-mgmt-tools list
Fedora Virtualization List
This section contains the discussion happening on the fedora-virt list.
F12 Feature: Host Information
Richard Jones posted[1] an RFC for a feature[2] he's working on for Fedora 12. The feature will "Allow a virtual machine to see information and statistics from the host operating system."
For example, it will "Allow a virtual machine to look at host information (such as number of physical, not just virtual CPUs), and statistics like the load on the host."
Daniel Berrange noted[3] that "a core goal of this hostinfo service is to avoid any use of networking. We don't want to presume that a guest has a NIC, nor that the host has a configured NIC on the same LAN as the guest." So this feature will make use of serial ports to pass queries and responses between the guest and the host.
libguestfs Super-minimized Appliance
Richard Jones
created[1]
a set of "very experimental" patches to
"which allow you to build a so-called 'supermin (super-minimized) appliance'."
libguestfs
Within libguestfs
, "The normal appliance is a self-contained Linux operating system, based
on the Fedora/RHEL/CentOS Linux distro. So it contains a complete
copy of all the libraries and programs needed, like kernel, libc,
bash, coreutils etc etc."
"The supermin appliance removes the kernel and all the executable libraries and programs from the appliance. That just leaves a skeleton of config files and some data files, which is obviously massively smaller than the normal appliance. At runtime we rebuild the appliance on-the-fly from the libraries and programs on the host (eg. pulling in the real /lib/libc.so, the real /bin/bash etc.)"
"The new appliance is a mere 500K, so libguestfs
RPMs will be a lot
smaller. Of course that just means they will have many more
dependencies, so the amount pulled down will be the same or greater."
A guest fish in the pipes
Richard Jones
patched[1]
. "This patch adds support for pipes to guestfish, so you can pipe output
from a guestfish
guestfish
command through a command on the host. The canonical
example is:
><fs> hexdump /bin/ls | less
Another example, looking for root backdoors in the password file:
><fs> cat /etc/passwd | awk -F: '$3 == 0 { print }' | grep -v ^root:
Anything right of the first pipe symbol gets passed to the local shell, thus expansion, redirection and so on work on that."
Libvirt List
This section contains the discussion happening on the libvir-list.
Safe PCI Device Passthrough
Mirko Raasch
asked[1]
"How can i start my guest with three pci devices passed through and
?" Starting libvirt
qemu
by hand appeared to work.
But virsh start produced an error:
libvirtd: 15:44:55.459: warning : pciTrySecondaryBusReset:483 : Other devices on bus with 0000:05:01.0, not doing bus reset
Daniel Berrange
recalled[2]
"what libvirt
is complaining about is that there are other devices
in the PCI bus which are not associated with this guest, and thus there
is no way to safely reset the device you are trying to assign, without
endangering the host OS or other guest OS."
Adding "when you launch QEMU manually there is no checking for whether the PCI devices are in use by other guests, or by the host OS. So while it may launch QEMU, it is not running safely, and eg, if your guest OS does a PCI bus reset it could kill/harm your host OS."
PCI device passthrough is a new feature[3] in Fedora 11.
VMware ESX driver status update
Matthias Bolte
continued[1] work (FWN #177[2]) to create a VMware ESX driver for libvirt
.
Matthias is currently "working on the VMX config to domain XML mapping for dump/create XML" using the VMware Infrastructure API[3].