From Fedora Project Wiki


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

Good Bye to ET-Mgmt-Tools List

Daniel Berrange announced[1] the end of life for the et-mgmt-tools list and the birth of the @virt-tools-list. "In retrospect this was a really bad choice of names for a mailing list and causes endless confusion for people wrt what to discuss where. Most of the emerging technology projects have lists of their own (Package-x-generic-16.pngcobbler[2][3], Package-x-generic-16.pngaugeas[4], Package-x-generic-16.pnglibguestfs[5], Package-x-generic-16.pnglibvirt[6]) and it is about time that Package-x-generic-16.pngvirt-manager and friends joined them."

"To that end we have created a new mailing list 'virt-tools-list'[7]. This will be the new home for all developer & user discussions relating to the following applications:"

  • virt-manager
  • virt-viewer
  • virt-install
  • virt-clone
  • virt-image
  • virt-convert

Fedora Virtualization List

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

Virtual Machine Disk Setup Tips

Rich Mahn recognized[1] "that the best performance for virtual disks is with the backing storage on the host being a parititon or LV. Since I want some flexibility I will use LVs, with virtio disks on most of the VMs." But Rich had several questions (paraphrased below) about how best to configure the backing stores for virtual machines and the disks within them. Daniel Berrange provided some answers (also paraphrased below).

  • Q: If each VM needs three file systems: /boot, root, and swap. "Is it better to create three LVs (each) on the hosts, and treat it as three separate disks on the VMs?"
A: "There's no point separating /boot & root onto separate virtual disks." "The only separation I'd do is for the OS system disks, vs application data disks..." This makes it easier to provision a new VM with the latest disto and reassign the data disk to the new guest.
  • Q: "Do I get better performance/stability by NOT using lvm on the VMs?"
A: "LVM makes is easier to resize guest FS. eg add a second disk to the guest, format it as a LVM PV and add it to your VG. That's pretty much only wayto add more capacity on a running guest."
  • Q: "Do I get the best performance/stability by creating an LV for each disk I need, and then NOT partitioning it on the VM, but using the whole disk for a file system?"
A: "Anaconda will refuse to install onto a raw disk, it mandates partitioning. Second point is that not using a partition table can cause unexpected problems..."
  • Q: "Are these issues too miniscule in their effects that I probably shouldn't even be worrying about" trying to avoid using partitions and LVM?
A: "That's certainly my opinion. Sure you get some performance but you loose the great administrative flexibility of LVM."

Libguestfs List

This section contains the discussion happening on the libguestfs list.

New Release libguestfs 1.0.59

Richard Jones announced[1] the release of Package-x-generic-16.pnglibguestfs 1.0.59.

New Features:

  • Support for Linux extended attributes.
  • Allow guestfish to be controlled remotely, so you can use one guestfish instance in a long-running shell script.
  • Support for reiserfs.
  • New function 'guestfs_zfile' -- 'file' inside compressed files.
  • New guestfish command 'reopen' -- reopen guestfish connection.
  • guestfish -x option (echo commands).
  • New function 'guestfs_version' to get the library version.

See previous release announcement for 1.0.57 in FWN#184[2] and be sure to see the project homepage[3] for extensive usage examples.

New Hypervisor Migration Tool virt-v2v

Matthew Booth posted[1] his "initial thoughts on the design for the v2v tool". This tool will be used to implement the planned Fedora 12 feature "Xen to KVM Migration"[2].

Libvirt List

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

Split RPC Dispatching from Remote API Handlers

Daniel Berrange posted[1] a set of 9 patches. "The current libvirtd remote protocol dispatch code is written in such a way that assumes the only incoming messages from clients are method calls. This makes it very hard to support data streams. This patch series does an incrmental refactoring of alot of code to allow data streams to be easily wired in."

Allow QEMU VMs to be Run Unprivileged

Daniel Berrange submitted[1] a patch which "makes it such that the" privileged "libvirtd daemon can run unprivileged QEMU guests. The default remains unchanged with QEMU running as root:root, but the package maintainer can request an alternative default user at build time, and the sysadmin can also override this at install time with /etc/libvirt/qemu.conf."

This patch is in support of the planned Fedora 12 feature "VirtPrivileges"[2].

cgroups Support in QEMU Driver

Daniel Berrange added[1] "cgroups[2] support to the QEMU driver."

Experimental Tunnelled Migration

Chris Lalancette posted[1] "the current version of the tunnelled migration patch, based upon Daniel Berrange's generic datastream work. In order to use this work, you must first grab danpb's data-streams git branch[2]". Chris's work on secure guest migration was covered in FWN #168[3].