Red Hat SummitChapter 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 listcommand to list active domains:xm list
$ xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 520 2 r----- 1275.5 r5b2-mySQL01 13 500 1 -b---- 16.1Copy to Clipboard Copied! Toggle word wrap Toggle overflow 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 pausexm unpausexm savexm 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-listto list virtualized CPU affinities:Copy to Clipboard Copied! Toggle word wrap Toggle overflow xm vcpu-pinxm vcpu-set- use the
xm sched-creditcommand to display scheduler parameters for a given domain:xm sched-credit -d 0 xm sched-credit -d 13
$ xm sched-credit -d 0 {'cap': 0, 'weight': 256} $ xm sched-credit -d 13 {'cap': 25, 'weight': 256}Copy to Clipboard Copied! Toggle word wrap Toggle overflow
Monitoring and troubleshooting options
Use the following xm commands for monitoring and troubleshooting:
xm topxm dmesgxm infoxm log- use the
xm uptimeto display the uptime of guests and hosts:xm uptime
$ xm uptime Name ID Uptime Domain-0 0 3:42:18 r5b2-mySQL01 13 0:06:27Copy to Clipboard Copied! Toggle word wrap Toggle overflow xm sysrqxm dump-corexm renamexm domidxm domname
Currently unsupported options
The xm vnet-list is currently unsupported.
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