xm(1M) (man pages section 1M: System Administration Commands)

man pages section 1M: System Administration Commands

xm(1M)

Name

xm– xVM management user interface

Synopsis

xm subcommand [options] domain

Description

The main interface for command and control of both xVM and guest domains is virsh(1M). Users should use virsh wherever possible, as it provides a generic and stable interface to controlling virtualized operating systems. Some xVM operations are not yet implemented by virsh. In those cases, the legacy utility xm can be used for detailed control.

With minor variations, the basic structure of an xm command is:

xm subcommand [options] domain

...where subcommand is one of the subcommands listed below, domain is the domain name (which is internally translated to a numeric domain id), and options are subcommand-specific options. The exceptions to this structure occur where a subcommand acts on all domains, on the entire machine, or directly on the xVM hypervisor. These exceptions are obvious in the descriptions of the subcommands.

All xm operations rely upon the xVM control daemon, xend(1M). xend must be running before any xm commands can run. As described in the man page, xend runs under the service management facility (smf(5)), which enables the daemon to start when a system is booted.

Most xm subcommands require either root privileges or that you assume the Primary Administrator role.

Most xm commands act asynchronously, so the fact that an xm command returns immediately does not mean that the requested action is complete. Many operations on domains, such as create and shutdown, can take considerable time (30 seconds or more) to complete.

Subcommands

The xm program supports the subcommands listed below. The parameters and options for a given subcommand are described in the description for that subcommand.

block-attach domain be-dev fe-dev mode [bedomain]

Create a new virtual block device. This will notify the guest domain of the new virtual block device..

The block-attach subcommand has the following arguments and options:

domain: The guest domain name to which the device will be attached.
be-dev: The device in the backend domain (domain 0) to be exported. This can be specified as a physical partition (for example, phy:/dev/md/dsk/mydisk, a ZFS volume or a normal file ('file:/export/disk-image').
fe-dev: The form, either a symbolic name or a numeric id, by which a device should be identified to the guest domain. In Linux, an example of a symbolic name is /dev/hdc. For Solaris guest domains, a single number should be used. The specified number will correspond to a Solaris disk ID. For example, disk ID 3 will have a slice 0 name of /dev/dsk/c0d3s0.
mode: The access mode for the device from the guest domain. Supported modes are w (read/write) and r (read-only).
bedomain: The backend domain hosting the device. This defaults to domain 0. Currently, no other ID is supported.

See EXAMPLES for an example of the use of this subcommand.

block-configure domain back_dev front_dev mode [back_domain]

Change block device configuration. Used for changing CDs in an HVM (hardware-based virtual machine) domain; in particular, changing the backend device to refer to a different ISO file. See block-attach for parameter descriptions.

block-detach domain dev-id

Destroy a domain's virtual block device. devid must be the device id given to the device by domain 0. You must run xm block-list to determine that number.

block-list [-l|--long] domain

List virtual block devices for a domain. The block-list subcommand has a single option:

-l, --long: Display output in long format.

console domain

Attach to domain domain's console. If you have set up your domains to have a text–based login console, you receive a normal login screen.

The console supports only paravirtualized domains. The attached console performs similarly to a serial console.

control-] exits the virtual console.

create [option] -f=config-file [name=value]...

The create subcommand creates a domain, according to the specifications in the mandatory config-file argument. create optionally accepts a set of name-value pairs that can override or add to the variables defined in config-file.

config-file can be an absolute pathname.

The create subcommand returns immediately upon domain startup. However, the starting of a domain is independent of the booting of the guest operating system in that domain and independent of that OS's availability for input.

The create and new subcommands are legacy features. These subcommands are used for existing domains that use the old configuration file format. New domains should be created with virt-install(1M).

The create subcommand has the following options:

-c --console_autoconnect: Attach to the console of the domain as soon as it has started.
-f=file, --defconfig=file: Use the given Python configuration script, file.The configuration script is loaded after arguments have been processed. Each command-line option sets a configuration variable named after its long option name, and these variables are placed in the environment of the script before it is loaded. Variables for options that can be repeated have list values. Other variables can be set using var=value on the command line. After the script is loaded, option values that were not set on the command line are replaced by the values set in the script.
-F=file, --config=file: Use the given SXP-format configuration file. This is an internal format; this option is useful only for debugging purposes.
-h, --help: Display list of options for create subcommand.
--help_config: Display the available configuration variables (vars) from the configuration script.
-n, --dryrun: Dry run. Displays the resulting configuration in SXP but does not create the domain.
-p, --paused: Leave the domain paused after it is created.
-q, --quiet: Display no messages over the course of domain creation.

debug-keys keys

Send commands to the hypervisor debugger. The keys are as follows:

% (ASCII 25): Trap to xendbg.
C (ASCII 43): Trigger a crash dump.
H (ASCII 48): Dump heap info.
N (ASCII 4e): NMI statistics.
O (ASCII 4f): Toggle shadow audits.
R (ASCII 52): Reboot machine.
S (ASCII 53): Reset shadow page tables.
a (ASCII 61): Dump timer queues.
d (ASCII 64): Dump registers.
h (ASCII 68): Display list of debug keys.
i (ASCII 69): Dump interrupt bindings.
m (ASCII 6d): Memory info.
n (ASCII 6e): Trigger an NMI.
q (ASCII 71): Dump domain (and guest debug) info.
r (ASCII 72): Dump run queues.
t (ASCII 74): Display multi-CPU clock info.
u (ASCII 75): Dump Non-Uniform Memory Access (NUMA) info.
v (ASCII 76): Dump Intel's VMCS.
z (ASCII 7a): Print ioapic info.

delete domain

Removes the domain domain from xVM domain management. This is the same as the virsh(1M) undefine, which should be used in place of this subcommand.

destroy domain

Immediately terminate the domain domain. For the domain OS, this is the equivalent of abruptly removing the power from a physical machine. In most cases, you will want to use the shutdown command instead.

dmesg [-c]

Displays recent messages in the xVM message buffer; analogous to dmesg(1M). The message buffer contains informational, warning, and error messages created during xVM's operation.

The dmesg subcommand supports the following option:

-c, --clear: Clears xVM's message buffer.

domid domain

Converts a domain name to a domain ID.

Domain IDs change on each boot, whereas names are permanent. See xVM(5) for an explanation of the differences among a domain ID, UUID, and name.

domname domain

Converts a domain ID to a domain name.

dump-core domain [output-file]

Dumps core for the domain domain. By default, the domain continues to run after a dump is collected. If output-file is not specified, the domain core dump is generated in /var/xen/dump/. Core dump files can be large. Solaris guest domain cores can be debugged using mdb(1).

The dump-core domain has the following options:

-C, --crash: Crash domain after dumping core.
-L, --live: Dump core without pausing the domain.

help [-l, --long]

Displays a list of common xm subcommands. xm help supports the following option:

-l, --long: Display a complete list of xm subcommands, grouped by function.

info

Display information about the xVM host in name : value format. The information reported by info is useful for inclusion in a bug report.

list [-l, --long] [domain, ...]

Displays information about one or more domains. If no domains are specified, displays information about all domains.

An example of list output:

Name                          ID   Mem VCPUs      State   Time(s)
Domain-0                       0  3456     2     r-----    244.7
solaris                        1   511    30     -b----    353.8

The fields in this output are as follows:

Name: Domain name
ID: Numeric domain ID.
Mem: Amount of memory, in MB, currently allocated to a domain.
VCPUS: Number of virtual CPUs assigned to a domain.
State: Run state (described below).
Time: Total run time of the domain as accounted for by xVM.

The State field in xm list output can, for a given domain, display one of the following letters.

r: Running. The domain is currently running on a CPU.
b: Blocked. The domain is not currently running. It is either idle or waiting on I/O.
p: Paused. The domain has been paused, occurring usually as a result of an administrator running xm pause. When in a paused state the domain still consumes allocated resources, such as memory, but will not be eligible for scheduling by the xVM hypervisor. See also the virsh suspend subcommand.
s: Shutdown. The domain is in the state it was in prior to startup. This state will, most likely, never be visible.
c: Crashed. The domain has crashed, which means that it terminated in an abrupt, unexpected manner. Usually this state can occur only if the domain has been configured not to restart on crash.
d: Dying. The domain is in process of moving to a shutdown or crashed state.

The list subcommand supports the following option:

-l, --long: Displays more detailed information about each domain than is shown in the standard list output table.

log

Display the xend(1M) log. The log file is /var/log/xen/xend.log.

mem-max domain mem

Specify the maximum amount of memory a domain is able to use. mem is specified in megabytes.

The mem-max value might not correspond to the actual memory used in a domain, because a domain might scale down its memory usage to return memory to the OS.

mem-set domain mem

Set the amount of memory used by the running domain domain. Because this operation requires cooperation from the domain operating system, there is no guarantee that it will succeed.

Warning: There is no good way to know in advance how small of a mem-set value will make a domain unstable and cause it to crash. Be very careful when using this command on running domains. Solaris guest domains attempt to refuse potentially dangerous settings.

migrate [options] domain host

Migrate a domain to another host machine. On the target host machine, the following conditions must obtain for this subcommand to be successful:

The other host must be running the same version of xVM.
The migration TCP port must be open and accepting connections from the source host.
There must be sufficient resources—memory, disk, and so forth—for the domain to run.

See xend(1M) for an explanation of how to set up a machine to receive a remote migration.

The domain's accessible disks must reside on some form of shared storage, such as NFS files or iSCSI volumes, and this storage must be accessible to both hosts

The migrate subcommand supports the following option:

-l, --live: Use live migration. This option migrates the domain between hosts without shutting down the domain.

network-attach domain [script=scriptname] [ip=ipaddr] [mac=macaddr] [bridge=link] [backend=bedomain] [rate=bandwidth] [vlan=vid]

Creates a new network device in the domain specified by domain. The subcommand has the following arguments:

domain

Domain in which the network device is to be created.

script=scriptname

Use the specified script name to bring up the network.

ip=ipaddr

Passes the specified IP address to the adapter upon creation. This address might be ignored by the specified domain.

mac=macaddr

The MAC address that the domain will see on its Ethernet device. If the MAC address is not specified, it will be randomly generated with the 00:16:3e vendor id prefix.

bridge=link

The name of the network link to which to attach a virtual interface, in case you have more than one.

backend=bedomain

The backend domain id. By default, this is domain 0. Note that backend != 0 is not currently operational.

rate=bandwidth

Sets the bandwidth limit for this interface. The bandwidth should be expressed in a regular expression defined as follows:

^([0-9]+)([GMK]?)([Bb])/s(@([0-9]+)([mu]?)s)?$

Note that bandwidth will be rounded up to 1.2M if the figure you input is below that value.

vlan=vid

Sets the VLAN ID for this interface.

network-detach domain dev-id

Removes the network device from the domain specified bydomain. dev-id is the virtual interface device number within the domain.

network-list [-l|--long] domain

List virtual network interfaces for a domain.

-l, --long: Display output in long format.

new domain

The new subcommand creates (but does not start) the domain defined by the given configuration file.

The new and create subcommands are legacy features. These subcommands are used for existing domains that use the old configuration file format. New domains should use virt-install(1M).

-f=file, --defconfig=file: Use the given Python configuration script, file.The configuration script is loaded after arguments have been processed. Each command-line option sets a configuration variable named after its long option name, and these variables are placed in the environment of the script before it is loaded. Variables for options that can be repeated have list values. Other variables can be set using var=value on the command line. After the script is loaded, option values that were not set on the command line are replaced by the values set in the script.
-F=file, --config=file: Use the given SXP-format configuration file. This is an internal format; this option is useful only for debugging purposes.
--help_config: Display the available configuration variables (vars) from the configuration script.
-n, --dryrun: Dry run. Displays the resulting configuration in SXP but does not create the domain.

npiv-add domid [-p virtual_port_WWN] [-n virtual_node_WWN] physical_port_WWN[, physical_port_WWN...]

Add a configuration entry for the virtual_port_WWN and associated virtual_node_WWN to the domain specified by domid, along with candidate physical ports on which the virtual port could be created. If virtual port/node WWNs are not specified, they will be generated.

npiv-disable domid -p virtual_port_WWN

Delete the specified virtual port and associated storage devices from the domain. The virtual_port_WWN will be marked as disabled, regardless of whether the deletion succeeds.

npiv-enable domid -p virtual_port_WWN

Create the specified virtual port on the first available physical port. The virtual_port_WWN will be marked as enabled, regardless of whether the creation succeeds.

npiv-list domid

List all the virtual port WWNs in the domain along with:

virtual node WWN
list of candidate physical ports (see npiv-add)
storage over the virtual port, if any

npiv-mod domid -p virtual_port_WWN -n virtual_node_WWN physical_port_WWN[, physical_port_WWN...]

Modify the configuration entry of the virtual_node_WWN and the physical_port_WWN list with the specified virtual_port_WWN.

npiv-rm domid -p virtual_port_WWN

Remove the configuration entry of the virtual_port_WWN from the domain specified by domid.

pause domain

Pause a domain. When in a paused state the domain still consumes allocated resources, such as memory, but will not be eligible for scheduling by the xVM hypervisor.

reboot [options] domain

Reboot a domain. The effect of this subcommand is the same as if the domain had the init 6 command (see init(1M)) run from the console. Unless -w is specified, reboot returns as soon as it has initiated the reboot process, which can be significantly before the domain actually reboots.

The reboot subcommand supports the following options:

-a, --all: Reboot all domains.
-w, --wait: Wait for reboot to complete before returning. This might take an extended period, as all services in the domain will have to be shutdown cleanly.

rename oldname newname

Renames the domain oldname to newname.

restore state-file

Build a domain from an xm save state file. See the save subcommand.

resume domain

Resume the activities of the domain domain, which is in a suspended state as a result of the suspend subcommand.

save domain state-file

Saves a running domain to a file state-file, so that it can later be restored, using the restore subcommand. Once saved, the domain will no longer be running on the system, thus the memory allocated for the domain will be free for the use of other domains.

Note that network connections present before the save operation might be severed, as TCP timeouts might have expired.

sched-credit -d domain [-w weight|-ccap]

Get and set credit scheduler parameters for the specified domain. See xVM(5) for a description of the credit scheduler. Without the -w or -c options, the current settings for the given domain are shown. Otherwise, the relevant parameter is set.

The parameters to the sched-credit subcommand are as follows:

-c cap, --cap=cap: Set the maximum amount of CPU a domain can consume. A value of zero (the default) means no maximum is set. This value is expressed in percentage points of a physical CPU. For example, a value of 50 specifies a cap of half a physical CPU.
-d domain, --domain=domain: Domain for which to set scheduling parameters.
-w weight, --weight=weight: Set the relative weight of the domain. A domain with twice the weight will receive twice the CPU time as another domain, if CPU use is in contention. Valid weights are in the range 1-65536 and the default is 256.

sched-sedf domain period slice latency-hint extratime weight

Set Simple EDF scheduler parameters. This scheduler provides weighted CPU sharing in an intuitive way and uses realtime algorithms to ensure time guarantees. The Simple EDF scheduler is not the default scheduler used in xVM.

The parameters to the sched-sedf subcommand are as follows:

domain: The domain for which scheduling parameters applies.
period: The normal EDF scheduling usage, in nanoseconds.
slice: The normal EDF scheduling usage, in nanoseconds.
latency-hint: Scaled period if domain is performing heavy I/O.
extratime: Flag for allowing domain to run in extra time.
weight: Another way of setting CPU slice.

shell

Launches an interactive shell.

shutdown [options] domain

Gracefully shuts down a domain. The effect of this subcommand is the same as if the domain had the init 5 command (see init(1M)) run from the console. This subcommand coordinates with the domain OS to perform graceful shutdown. The duration of the entire shutdown will vary, depending on what services must be shutdown in the domain. The shutdown subcommand returns immediately after signalling the domain, unless the -w option is used.

The shutdown subcommand supports the following options:

-a: Shutdown all domains.
-w: Wait for the domain to complete shutdown before returning.

start domain

Start the domain specified by domain.

suspend domain

Suspend the activities of all services in the domain specified by domain.

sysrq domain letter

For the accepted signals in a Linux domain, refer to the Linux documentation. For Solaris signalling the letter b causes the domain to enter kmdb(1), the Solaris kernel debugger, if that debugger is loaded. Any other letter has no effect.

top domain...

Invokes the xentop(1M) command. Monitor a host and one or more domains in real time.

unpause domain

Moves the domain domain out of the paused state. This will allow a previously paused domain to now be eligible for scheduling by the xVM hypervisor. See the pause subcommand.

uptime domain

Provides information on resource usage for domain domain. Analogous to the uptime(1) command.

vcpu-list domain

Lists VCPU information for the domain domain. If no domain is specified, the subcommand provides VCPU information for all domains.

vcpu-pin domain vcpu cpus

Pins the VCPU to only run on the specified CPUs. The keyword all can be used to apply the cpus list to all VCPUs in the domain.

Normally VCPUs can float between available CPUs whenever xVM deems a different run state is appropriate. Pinning can be used to restrict this, by ensuring certain VCPUs can run only on certain physical CPUs.

vcpu-set domain vcpu-count

Enables the number vcpu-count of virtual CPUs for the domain in question. Like the mem-setsubcommand, vcpu-set can allocate only up to the maximum virtual CPU count configured at boot time for a domain.

If vcpu-count is smaller than the current number of active VCPUs, the highest numbered VCPUs will be hotplug removed. This might have consequences for pinned VCPUs.

Attempting to set the VCPUs to a number larger than the initially configured VCPU count is an error. Trying to set VCPUs to less than one will be silently ignored.

Examples

Example 1 Attach a File as a Read-only Block Device

The following example attaches a file as a read-only block device to a Solaris guest domain, as /dev/dsk/c0d3.

xm block-attach solaris1 file:/data/disk.img 3 r

Example 2 Live Migration of a `domU` to a Different Host

xm migrate --live solaris1 solaris-host2

Example 3 Pin a Domain's `vcpus` to Corresponding CPUs

xm vcpu-pin solaris1 0 5
xm vcpu-pin solaris1 1 6

Example 4 Balloon Down a Domain to Use Less Memory

xm mem-set solaris1 512

Authors

Sean Dague, sean at dague dot net
Daniel Stekloff, dsteklof at us dot ibm dot com
Reiner Sailer, sailer at us dot ibm dot com

Attributes

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Availability	SUNWxvmu
Interface Stability	Volatile