Index of /xen/cent7/dom0

[ICO]NameLast modifiedSizeDescription

[DIR]Parent Directory  -  
[DIR]build_craft/03-Jan-2016 22:47 -  
[DIR]RPMS/12-Jan-2018 10:43 -  
[DIR]SRPM/08-Aug-2015 13:38 -  
[   ]add_lvm.conf27-Jul-2014 00:02 119  
[TXT]c7-comps.html01-Aug-2014 11:42 237K 
[IMG]isp_speed.png18-Sep-2014 12:58 32K 
[TXT]list-unit-files.txt25-Aug-2014 16:09 1.0K 
[TXT] 22:27 746  
[TXT] 10:32 1.6K 
[   ]ovmf-dir.tar.gz11-Oct-2015 07:42 31M 
[TXT]patch_declare.lua26-Dec-2015 16:31 329  
[   ]seabios-dir.tar.gz.173122-Apr-2015 19:10 468K 
[IMG]status-xendomains.jpeg26-Jul-2014 23:51 101K 
[TXT]status-xendomains.txt27-Jul-2014 18:41 1.1K 
[TXT]xen-git-readme.txt05-Sep-2014 09:10 1.6K 
[TXT]xen.git.config-mk.2release.patch05-Sep-2014 22:06 817  
[TXT]xl_info.txt16-Jul-2014 23:34 3.2K 

Install Xen 4.4.x in EL7 with Mainline kernel(kernel-ml)

Here you can get a method to setup a recent Xen (stable-4.4), with a recent kernel, in Centos 7 (el7). Resources to install 4.5.x are located here. The build has support for systemd, has upstream qemu (unlike the fc22 result), and has been tested with success after only a few simple edits of the systemd unit files. The xen packages are from a rebuild of You can fetch the xen.spec from any of the SRPM.

Early LVM Discovery

There is one important patch to allow xendomains.service to launch any lvm based VM: Locate your lvm.conf, usually in /etc/lvm/lvm.conf Change `use_lvmetad = 1` -> `use_lvmetad = 0` Without the above mod, the lvm2 disks are unseen until almost the end of boot- too late for xen. If you want to run with `use_lvmetad=1` (it boots faster), then see the indexed script This script will make a Systemd Drop-In config that will sequence xendomains.service so that pvscans are done in advance. A sample looks like add_lvm.conf.

Which Kernel?

The default C7 kernel is ala Red Hat, where Xen dom0 support is disabled. The domU support is mostly there, except for vfb objects. In mainline kernel there are 40 or more Xen config settings, since its been supported here since 3.1+. Red Hat has made a political statement, halved this support and customised their kernel to be almost xenless.

Using elrepo-kernel

You can find an el7 kernel with full mainline configuration at the elrepo-kernel repo. The package is called kernel-ml. In my `xl info` trace you can see which kernel I use, and its version. It works very well as Xen dom0 or domU, and there is no problem from systemd.

Tuning kernel-ml for Xen

Recently I contacted the Packager of kernel-ml in #elrepo on I requested 2 changes in Xen config for any future release. These changes were made: CONFIG_XEN_FBDEV_FRONTEND=m (previously, unset) CONFIG_XEN_PCIDEV_BACKEND=y (from =m) The next release, on August 4, included the above changes. With the elrepo-nosrc-system, it's not too difficult to rebuild kernel-ml yourself - consuming about 7000 cpu seconds. But, when you can request changes from upstream it simplifies things.

Subsystem Versions

ocaml -version The OCaml toplevel, version 4.00.1 qemu-system-i386 -version QEMU emulator version 1.6.2, Copyright (c) 2003-2008 Fabrice Bellard

Services in minimal dom0

Here is a list of systemd services for dom0.

5 git repos in stable-4.4

For a list of the git repos used in xen-4.4.1 stable, see xen-git-readme.txt

Difference between release tarball and git config files

Its important to know that before they move from git and make a release tarball, some important files are changed: namely xen-4.4.1/ I have a patch indexed here, as xen.git.config-mk.2release.patch

Xen Balloon kernel messages

In recent kernel-ml you might see these messages: xen:balloon: reserve_additional_memory add_memory() failed: -17 To stop these, you can leave as default: /etc/xen/xl.conf -> #autoballoon="auto" But in your xen.gz cmdline params, allow 16MB/VM to your max memory, like this: dom0_mem=512M,max:608M for six virtual machines. Result ------ You will end up with a functioning dom0 with about 436 packages. Here is `xl info` for the new el7 dom0. Author ------ msp July 16, 2014