Chapter 28. The xm command quick reference
The
xm
command can manage the Xen hypervisor. Most operations can be performed with the libvirt tools, virt-manager application or the virsh
command. The xm
command does not have the error checking capacity of the libvirt tools and should not be used for tasks the libvirt tools support.
There are a few operations which currently can not be performed using virt-manager. Some options for other Xen implementations of the
xm
command do not work in Red Hat Enterprise Linux 5. The list below provides an overview of command options available and unavailable.
Warning
It is advised to use
virsh
or virt-manager
instead of xm
. The xm
command does not handle error checking or configuration file errors very well and mistakes can lead to system instability or errors in virtual machines. Editing Xen configuration files manually is dangerous and should be avoided. Use this chapter at your own risk.
Basic management options
The following are basic and commonly used xm
commands:
xm help [--long]
: view available options and help text.- use the
xm list
command to list active domains:$ xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 520 2 r----- 1275.5 r5b2-mySQL01 13 500 1 -b---- 16.1
xm create [-c] DomainName/ID
: start a virtual machine. If the -c option is used, the start up process will attach to the guest's console.xm console DomainName/ID
: attach to a virtual machine's console.xm destroy DomainName/ID
: terminates a virtual machine , similar to a power off.xm reboot DomainName/ID
: reboot a virtual machine, runs through the normal system shut down and start up process.xm shutdown DomainName/ID
: shut down a virtual machine, runs a normal system shut down procedure.xm pause
xm unpause
xm save
xm restore [-p] DomainName/ID
: resume the state, and the execution of the domain. If the -p option is used, the domain will not be unpaused after restoring it.xm migrate
Resource management options
Use the following xm
commands to manage resources:
xm mem-set
- use the
xm vcpu-list
to list virtualized CPU affinities:$ xm vcpu-list Name ID VCPUs CPU State Time(s) CPU Affinity Domain-0 0 0 0 r-- 708.9 any cpu Domain-0 0 1 1 -b- 572.1 any cpu r5b2-mySQL01 13 0 1 -b- 16.1 any cpu
xm vcpu-pin
xm vcpu-set
- use the
xm sched-credit
command to display scheduler parameters for a given domain:$ xm sched-credit -d 0 {'cap': 0, 'weight': 256} $ xm sched-credit -d 13 {'cap': 25, 'weight': 256}
Monitoring and troubleshooting options
Use the following xm
commands for monitoring and troubleshooting:
xm top
xm dmesg
xm info
xm log
- use the
xm uptime
to display the uptime of guests and hosts:$ xm uptime Name ID Uptime Domain-0 0 3:42:18 r5b2-mySQL01 13 0:06:27
xm sysrq
xm dump-core
xm rename
xm domid
xm domname
Currently unsupported options
The xm vnet-list
is currently unsupported.