Integrating Xen 4.2 with Systemd.

xen-and-systemd

Integrating Xen 4.2 AUR with Systemd.
=================================

I tested the AUR package with a fresh installation of Arch of x86_64. Only 
packages 'base', 'base-devel'and the dependencies mentioned on the site 
were installed.
  * package build also requires dev86
  * dev86 is in multilib, x86_64 users need to enable multilib in /etc/pacman.conf 

  * users need to add a new entry to their bootloader config file   (mentioned)
  * users need to set up a network bridge or alternative for dom0 (not mentioned)

The following are what was needed to make systemd work successfully with the AUR package 
(and the installation from xen.org source).

* Need to include the following line in /etc/fstab:
    none /proc/xen xenfs defaults 0 0

* Need to place the file 'xendomains' (created in init.d) somewhere useful. 
  Fedora use /usr/libexec which Arch does not have. It's a script so maybe 
  /etc/xen/scripts/ ?

* Error messages about 'failed to execute /usr/lib/.... xend/udev_event'
  (lots of them) are caused by /etc/udev/rules.d/xend.rules
  As xend is (a) deprecated and (b) not used, it is safe to remove xend.rules

  I was able to remove /etc/udev/xen-backend rules without any (apparent) effect.

* The AUR build creates both oxenstored and censtored. oxenstored is more
  efficient according to xen.org so oxenstored.service is provided.

* The following files integrate Xen 4.2 with systemd 195. They replace xencommons
  which loads startup modules then starts oxenstored, xenconsoled and xendomains.
 
  To start the services at startup, issue:
    systemctl enable oxenstored.service
    systemctl enable xenconsoled.service
    systemctl enable xendomains.service

---------------------------------------------------------------------------------
  /etc/modules-load.d/xen.conf
---------------------------------------------------------------------------------

	 xen-evtchn 
	 xen-gntdev 
	 xen-gntalloc 
	 xen-blkback 
	 xen-netback 
	 xen-pciback 
	 xen-acpi-processor 
# The following were included in xencommons, but were not inserted by systemd
#	 evtchn 
#	 gntdev 
#	 netbk 
#	 blkbk 
#	 xen-scsibk 
#	 usbbk 
#	 pciback 
#	 blktap2
#	 blktap
	
#### end of xen.conf

---------------------------------------------------------------------------------
  /usr/lib/systemd/system/xenstored.service
---------------------------------------------------------------------------------

[Unit]
Description=Xenstored - daemon managing xenstore file system
Before=libvirtd.service libvirt-guests.service
After=dbus.service
RefuseManualStop=true

[Service]
Type=forking
PIDFile=/var/run/xenstored.pid
ExecStart=/usr/sbin/xenstored --pid-file /var/run/xenstored.pid $XENSTORED_ARGS

[Install]
WantedBy=multi-user.target

#### end of xenstored.service


---------------------------------------------------------------------------------
  /usr/lib/systemd/system/xenconsoled.service
---------------------------------------------------------------------------------

[Unit]
Description=Xenconsoled - handles logging from guest consoles and hypervisor
After=xenstored.service

[Service]
Type=simple
PIDFile=/var/run/xenconsoled.pid
ExecStart=/usr/sbin/xenconsoled 

[Install]
WantedBy=multi-user.target

#### end of xencommons.service


---------------------------------------------------------------------------------
  /usr/lib/systemd/system/xendomains.service
---------------------------------------------------------------------------------

[Unit]
Description=Xendomains - start and stop guests on boot and shutdown
Requires=proc-xen.mount xenstored.service
After=proc-xen.mount xenstored.service xenconsoled.service
ConditionPathExists=/proc/xen

[Service]
Type=oneshot
RemainAfterExit=true
ExecStartPre=/usr/bin/grep -q control_d /proc/xen/capabilities
ExecStart=/etc/xen/scripts/xendomains start
ExecStop=/etc/xen/scripts/xendomains stop

[Install]
WantedBy=multi-user.target

#### end of xendomains.service


********************************************************************************
 xen.conf paleo9

 oxenstored.service xenconsoled.service xendomains.service
   based on Fedora 17, modified for the Arch system by paleo9
*********************************************************************************