FWN/Beats/Virtualization

Virtualization

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

Contributing Writer: Dale Bewley

Fedora Virtualization List

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

Guest Bridge Configuration with libvirt and netcf

Andrés García thought he read somewhere that with Fedora 12 there was going to be a way to configure virtual network bridges automagically", but was only aware of the manual means of configuration.

It is possible in to configure bridges using virsh thanks to the Network Interface Management feature and netcf. However, the process is manual and not in the GUI. Dale Bewley blogged about how to manually create a bridge in Fedora 12 using virsh.

Support for virt-manager integration is targeted for Fedora 13.

New Release libguestfs 1.0.78

Richard Jones announced version 1.0.78 of libguestfs, the library for accessing and modifying virtual machine filesystems.

New Features:

• FUSE support so you can mount guest filesystems in the host
• Support for btrfs, gfs, gfs2, hfs, hfs+, nilfs2, jfs, reiserfs, xfs
• Support for huge (multi-exabyte) sparse virtual disks
• New partitioning API, supports GPT and more
• New tools:

• virt-ls
• virt-tar
• virt-edit
• virt-rescue

• Windows Registry support, tools and library
• OCaml bindings for virt-inspector
• RELAX NG schema for virt-inspector
• New APIs: utimens, vfs_type, truncate, truncate_size, lchown, lstatlist, lxattrlist, readlinklist, case_sensitive_path, find0, mkfs_b, mke2journal, and more ...
• New program: OCaml viewer
• Allow stdout to be redirected when running guestfish remotely (Matt Booth).
• Remove requirement for vmchannel support in qemu (horray!) and the tricky main loop code.

Fedora Xen List

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

No Xen dom0 in Fedora 12 Hopefully 13

Zhang Enming was disappointed to learn the pv_ops dom0 support for hosting Xen guests, dropped in Fedora 9, is still not present in Fedora 12. Zhang referenced numerous videos documenting success in creating "a fully working Xen pv-ops dom0 Fedora 11 host operating system."

While there are experimental patches which may be applied to the kernel to enable support for dom0, they are not yet in the upstream kernel which forms the basis the Fedora kernel package.

It was decided two years ago this month that Fedora "simply cannot spend more time forward porting Xen kernels" and "the plan is to re-focus 100% of all Xen kernel efforts onto paravirt_ops." See FWN#137.

Pasi Kärkkäinen noted "pv_ops dom0 kernel has only recently started working for many/most people, so it was too late for F12 release" and "There are still some missing features, most notably missing blktap2 support for tap:aio: file-based images."

Libvirt List

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

Keeping Guest Configurations in Sync on Multiple Hosts

Thomas Treutner asked "is there any best-practice how to keep VM definitions in sync across a couple of hosts? Is it reasonable to put /etc/libvirt/qemu/ on a NFS share?"

Matthias Bolte explained "No, it's not safe to share /etc/libvirt/qemu/", but also didn't find it necessary to keep the configs in sync. "A migrated domain stays defined on the source node and is transient on the destination node. A transient domain has no persistent config on its node and is lost when destroyed."

Matthias mentioned a patch to the virDomainMigrate function by Chris Lalancette which will be in libvirt 0.7.3. The patch adds a new flag which will allow domains to be migrated persistently.