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Chapter 20. Managing guests with xend

The xend node control daemon performs certain system management functions that relate to virtual machines. This daemon controls the virtualized resources, and xend must be running to interact with virtual machines. Before you start xend, you must specify the operating parameters by editing the xend configuration file /etc/xen/xend-config.sxp. Here are the parameters you can enable or disable in the xend-config.sxp configuration file:

Table 20.1. xend configuration parameters

Item Description
Determines the console server's memory buffer limit and assigns that limit on a per domain basis.
Determines the minimum number of megabytes that is reserved for domain0 (if you enter 0, the value does not change).
Determines the number of CPUs in use by domain0 (at least 1 CPU is assigned by default).
If this is enabled, when a crash occurs Xen creates a dump file (the default is 0).
Determines the script or application that handles external device migration. The scripts must reside in the /etc/xen/scripts/external-device-migrate directory.
Determines the location of the log file (default is /var/log/xend.log).
Filters out the log mode values: DEBUG, INFO, WARNING, ERROR, or CRITICAL (default is DEBUG).
Determines the script that enables the networking environment. The scripts must reside in the /etc/xen/scripts/ directory.
Enables the http stream packet management server (the default is no).
Enables the UNIX domain socket server. The socket server is a communications endpoint that handles low level network connections and accepts or rejects incoming connections. The default value is set to yes.
Enables the relocation server for cross-machine migrations (the default is no).
Determines the location where the xend-unix-server command outputs data (default is /var/lib/xend/xend-socket)
Determines the port that the http management server uses (the default is 8000).
Determines the port that the relocation server uses (the default is 8002).
Determines the host addresses allowed for migration. The default value is the value of xend-address.
Determines the address that the domain socket server binds to. The default value allows all connections.
After setting these operating parameters, you should verify that xend is running and if not, initialize the daemon. At the command prompt, you can start the xend daemon by entering the following:
service xend start
You can use xend to stop the daemon:
service xend stop
This stops the daemon from running.
You can use xend to restart the daemon:
service xend restart
The daemon starts once again.
You check the status of the xend daemon.
service xend status
The output displays the daemon's status.


Use the chkconfig command to add the xend to the initscript.
chkconfig --level 345 xend
The xend will now start in runlevels 3, 4 and 5.