Linux and UNIX Man Pages

Test Your Knowledge in Computers #205
Difficulty: Easy
Routing Information Protocol (RIP) runs over Transmission Control Protocol (TCP).
True or False?
Linux & Unix Commands - Search Man Pages

virsh(1m) [opensolaris man page]

virsh(1M)						  System Administration Commands						 virsh(1M)

virsh - management user interface for guest domains SYNOPSIS
virsh subcommand [arguments] DESCRIPTION
The virsh command provides the main interface for command and control of both xVM and guest domains. Users should use virsh wherever possi- ble, as it provides a generic and stable interface to controlling virtualized operating systems. Some xVM operations are not yet imple- mented by virsh. In those cases, the legacy utility xm(1M) can be used for detailed control. Running on the SPARC platforms that support the Logical Domains (LDoms) software, the virsh command provides the interface for command and control of the logical domains. Some LDoms operations are not yet implemented by virsh. In those cases, use the ldm utility, supplied with Logical Domains Manager feature, for detailed control of LDoms. The ldm utility is documented in the ldm(1M) man page, which is shipped with the LDoms software and is not a SunOS man page. virsh can be used to administer both transient and managed guests. A managed guest has a persistent configuration which is maintained across multiple invocations of the guest. The configuration of a transient guest is discarded when the guest shuts down. With minor exceptions, the basic form of a virsh command is: # virsh subcommand domain-id | name | uuid [options] The components of a virsh command are described as follows: subcommand One of the subcommands described below. domain-id | name | uuid An identifier for a specific domain. options A subcommand-specific option. Exceptions to command form described above occur when a subcommand acts on all domains, the entire machine, or directly on the Solaris xVM hypervisor. Most virsh subcommands require root privileges or that you assume the Primary Administrator role. Many virsh commands act asynchronously, so that the system prompt returns immediately while activity proceeds in the background. Many oper- ations on domains, such as create and shutdown, can take considerable time (30 seconds or more) to reach completion. Use the list subcom- mand to determine whether such an operation is complete. SUBCOMMANDS
The virsh subcommands are categorized under the rubrics "generic", "domain", and "device" and are described in the following subsections of those names. Generic Subcommands capabilities Display an XML document describing the capabilities of the hypervisor to which we are currently connected. This includes a section on the host capabilities in terms of CPU features, and a description for each kind of guest which can be virtualized. For a more complete description, see the page under entitled "XML Format". The XML also shows the NUMA topology information, if available. connect URI [--readonly] Connect to the hypervisor. The URI parameter, if provided, specifies how to connect to the hypervisor. Without this parameter, the connection will be to the local hypervisor. The web page entitled "Connection URIs", under, lists the possible values, but not all types are supported by all systems. With the --readonly option, the connection is read-only. help [subcommand] With no argument, help displays a brief synopsis of all subcommands. With a specified subcommand, displays a brief description of that subcommand. nodeinfo Returns basic information about a node, such as the number and type of CPUs, and the size of physical memory. quit Quit this interactive terminal. version Display version information about this instance of virsh. Domain Subcommands The following subcommands manipulate domains directly. Most take a domain identifier as their first argument. In the following description, the notation domain can be either a symbolic domain name, a numeric domain id, or a UUID, any of which uniquely identify a domain. console domain Connect the virtual serial console for the guest. create file Create (and start) a domain based on the parameters contained in the XML file file, where file is an absolute pathname. Such a file can be created using virsh dumpxml subcommand. Directly editing XML configuration is not recommended. Use this subcommand to create a transient guest. Use define (below) to create a managed guest. define file [--relative-path path] Define (but do not start) a domain from the specified XML file. If the disk paths in the XML file contain relative paths, the domain will be created with those paths relative to path, if provided. destroy domain Immediately terminate a domain. This is the equivalent of abruptly terminating power to a machine. In most cases, you should use the shutdown subcommand instead. domid domain_name Converts a domain name to a numeric domain ID. dominfo domain Returns basic information about a domain. In dominfo output, note that the OS Type field displays the type of virtualization--hvm for a Hardware-assisted Virtual Machine (HVM), linux for a paravirtualized domain--not the guest OS installed in a domain. domname domain_id Converts a numeric domain id to a domain name. domstate domain Returns the state of a running domain. See the description of the list subcommand. domuuid domain Convert the specified domain name or ID to a domain UUID. dump domain file Dump the core of the domain specified by domain to the file specified by file for analysis. dumpxml domain [--relative-path path] Output the configuration of the given domain in XML format. Captured in a file, this data can be used as the argument to a subsequent create subcommand. By default, all paths in the XML will be absolute. Adding the --relative-path option will make all disk paths relative to path. list [domain...] Displays information about one or more domains. If no domains are specified, displays information about all defined domains. This sub- command takes the following options: --active Display only running domains. --inactive Display only non-running domains. --all Display both running and non-running domains. By default, all domains are displayed. An example of list output is as follows: % virsh list Id Name State ---------------------------------- 0 Domain-0 running 2 fedora paused - solaris-hvm shut off Id is the numeric id for a domain; Name is the symbolic name. State is the run state and can be one of the following: running The domain is currently running on a CPU. blocked The domain is not currently running on any CPU. This can be because the domain is waiting on I/O (a traditional wait state) or has gone to sleep because of inactivity. paused The domain has been paused, usually as a result of the administrator running virsh suspend. When in a paused state the domain still consumes allocated resources, such as memory, but is not eligible for scheduling by the xVM hypervisor. in shutdown The domain is in process of shutting down, but has not completely shutdown or crashed. shut off The domain is down. crashed The domain has crashed as a result of a sudden event. Normally, this state can occur only if the domain has been configured not to restart following a crash. migrate [--live] domain dest_uri [migrate_uri] Migrate the domain to the host specified by dest_uri. The --live option attempts a live migration. The optional migrate_uri is a sepa- rate URI that specifies a transport method between the host and destination. This option is usually not needed. reboot domain Reboot a domain. The effect of this command is identical to the effect of running init 6. The command returns immediately, however the entire reboot process might take a minute or more. restore state-file Restores a domain from a virsh save state file. See the description of the save subcommand. resume domain Moves a domain out of the paused state, making the domain eligible for scheduling by the underlying hypervisor. 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. schedinfo domain Show or set the scheduling paramaters for the specified domain name, ID or UUID. This subcommand takes the following options: --weight number weight for XEN_CREDIT --cap number cap for XEN_CREDIT setmaxmem domain kilobytes Change the maximum memory allocation limit in the specified guest domain. The kilobytes parameter is the maximum memory limit in kilo- bytes. setmem domain kilobytes Change the current memory allocation in the specified guest domain. The kilobytes parameter is the number of kilobytes of memory. setvcpus domain count Change the number of virtual CPUs active in the specified guest domain. The count parameter is the number of virtual CPUs. shutdown domain Coordinates with the domain OS to perform graceful shutdown. The effect of this command is identical to the effect of running init 5. There is no guarantee that the subcommand will succeed and it might take an unexpected length of time, depending on what services in the domain must be shutdown. start domain Start a (previously defined) inactive domain. suspend domain Suspend a domain. When in this state, a domain still consumes allocated resources, such as memory, but is not eligible for scheduling by the xVM hypervisor. undefine domain Undefine the configuration for the inactive domain which is specified by either its domain name or UUID. vcpuinfo domain Return basic information about the domain virtual CPUs. vcpupin domain vcpu cpulist Pin domain VCPUs to the host physical CPUs. The domain parameter is the domain name, ID, or uuid. The vcpu parameter is the VCPU num- ber. The cpulist parameter is a list of host CPU numbers, separated by commas. vncdisplay domain Output the IP address and port number for the VNC display. Device Subcommands The following subcommands manipulate devices associated with domains. In the following descriptions, domain can stand for either a symbolic domain name, a numeric domain id, or a UUID, any of which uniquely identify a domain. attach-device domain file Attach a device defined by the given XML file (file) to the specified domain. attach-disk domain source target --driver driver --subdriver subdriver --type type --mode mode Attach a new or existing disk device to the domain. A disk device can be a removable media device, such as a CD or DVD drive. source and target are paths for the files and devices. driver can be file, tap or phy, depending on the kind of access. type can indicate cdrom or floppy as an alternative to the default, disk. mode can specify either readonly or shareable. Note that in a Solaris Hardware-assisted Virtual Machine (HVM) domU, you must run eject(1) in the domU to unlock a removable-media device (for example, a CD device) before running the attach-disk subcommand. attach-interface domain type source --target target --mac mac --script script --capped-bandwidth bandwidth --vlanid vid Attach a new network interface to the domain. type can be either network, to indicate a physical network device, or bridge, to indicate a bridge to a device. source indicates the source device. The --target option allows you to specify the target device in the guest. --mac allows you to specify the MAC address of the network interface. --script specifies a path to a script handling a bridge. --capped-bandwidth sets the bandwidth for this interface. Bandwidth should be specified as an integer with one of the scale suffixes (K, M, or G for Kbps, Mbps, or Gbps, respectively). Bandwidth will be rounded up to 1.2M, if the input number is smaller than that. --vlanid sets the VLAN ID for this interface to vid. detach-device domain file Detach a device defined by the given XML file (file) from the specified domain. This subcommand takes the same type of XML descriptions as the subcommand attach-device. detach-disk domain target Detach a disk device from a domain. The target is the device as seen from the domain. detach-interface domain type --mac mac Detach a network interface from a domain. type can be either network, to indicate a physical network device, or bridge, to indicate a bridge to a device. It is recommended you use the --mac option to distinguish between the interfaces if more than one is present in the domain. EXAMPLES
Example 1 Adding an ISO File to a Solaris Domain as a Virtual Disk The following command adds an ISO file to a paravirtualized Solaris domain as a virtual disk /dev/dsk/c0t1d0. # virsh attach-disk --type cdrom --driver file --mode readonly domu-220 /data.iso xvdb Example 2 Migrating a Domain, Relying on sshd Configuration To migrate a domain named domu to a machine named foo over ssh(1), first create the ssh connection: # ssh -N -L 8003:localhost:8002 root@foo ...then run the virsh migrate command: # virsh migrate --live domu xen:/// xenmigr://localhost:8003 This example assumes that TCP port forwarding is allowed by sshd_config(4). Note that this example does not require any modification of xend(1M) properties. Example 3 Migrating a Domain, Relying on xend Configuration The following virsh migrate command requires the proper setting of the xend xend-relocation-address and xend-relocation-hosts-allow proper- ties, as described in the xend(1M) man page. # virsh migrate --live domu xen:/// xenmigr://remotehost Example 4 Changing a CD in a Solaris HVM Guest Domain The following sequence of commands attaches a CD drive to a guest domain. In the guest domain, eject the CD: solaris-hvm# eject cdrom Then, in the control domain, enter: # virsh attach-disk solaris-hvm --type cdrom --driver file --mode readonly /isos/solaris.iso hdc Finally, in the guest domain, load the CD: solaris-hvm# rmformat Example 5 Displaying dominfo Output The following command displays information about domain 0. # virsh dominfo Domain-0 Id: 0 Name: Domain-0 UUID: 00000000-0000-0000-0000-000000000000 OS Type: linux State: running CPU(s): 4 CPU time: 14436.6s Max memory: no limit Used memory: 3145728 kB In the preceding output, note that the OS Type, linux, indicates a paravirtualized domain. Example 6 Attaching an Interface The following command attaches a new network interface to a guest domain, connected to the NIC e1000g0, with an auto-generated MAC address (that is, the --mac option is omitted). # virsh attach-interface pv-domu bridge e1000g0 ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWlibvirt | +-----------------------------+-----------------------------+ |Interface Stability |Volatile | +-----------------------------+-----------------------------+ SEE ALSO
init(1M), xend(1M), xentop(1M), xm(1M), attributes(5), xVM(5) The ldm(1M) man page shipped with the LDoms software. The virtualization library (libvirt) web site, at the date of this publication, at: AUTHORS
o Andrew Puch, apuch at redhat dot com o Daniel Veillard, veillard at redhat dot com The preceding authors credit the xm man page authored by: o Sean Dague, sean at dague dot net o Daniel Stekloff, dsteklof at us dot ibm dot com NOTES
Terminology differs between xm(1M) and virsh. In particular, the suspend and resume commands have different meanings. virsh xm --------------------------------------------------------------------- suspend pause resume unpause save suspend (without output file argument) restore resume (without output file argument) Terminology for the domain states differs between LDoms utilities, such as ldm, and virsh. virsh LDoms utility ----------------------------------------------------------- running active shut off inactive in shutdown bound SunOS 5.11 21 Jan 2009 virsh(1M)

Featured Tech Videos