docs: introduce an xl man page in pod format

This is the initial version of an xl man page, based on the old xm man
page.  Almost every command implemented in xl should be present, a
notable exception are the tmem commands that are currently missing.
Further improvements and clarifications to this man page are very
welcome.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
This commit is contained in:
Stefano Stabellini committed 2011-11-01 18:44:34 +00:00
1 parent 7a545e0090
commit 5c7aad5247
1 file changed
+805
+805
View File
@@ -0,0 +1,805 @@
=head1 NAME
XL - Xen management tool, based on LibXenlight
=head1 SYNOPSIS
B<xl> I<subcommand> [I<args>]
=head1 DESCRIPTION
The B<xl> program is the new tool for managing Xen guest
domains. The program can be used to create, pause, and shutdown
domains. It can also be used to list current domains, enable or pin
VCPUs, and attach or detach virtual block devices.
The old B<xm> tool is deprecated and should not be used.
The basic structure of every B<xl> command is almost always:
=over 2
B<xl> I<subcommand> [I<OPTIONS>] I<domain-id>
=back
Where I<subcommand> is one of the subcommands listed below, I<domain-id>
is the numeric domain id, or the domain name (which will be internally
translated to domain id), and I<OPTIONS> are subcommand specific
options. There are a few exceptions to this rule in the cases where
the subcommand in question acts on all domains, the entire machine,
or directly on the Xen hypervisor. Those exceptions will be clear for
each of those subcommands.
=head1 NOTES
Most B<xl> operations rely upon B<xenstored> and B<xenconsoled>: make
sure you start the script B</etc/init.d/xencommons> at boot time to
initialize all the daemons needed by B<xl>.
In the most common network configuration, you need to setup a bridge in dom0
named B<xenbr0> in order to have a working network in the guest domains.
Please refer to the documentation of your Linux distribution to know how to
setup the bridge.
Most B<xl> commands require root privileges to run due to the
communications channels used to talk to the hypervisor. Running as
non root will return an error.
=head1 DOMAIN SUBCOMMANDS
The following subcommands manipulate domains directly. As stated
previously, most commands take I<domain-id> as the first parameter.
=over 4
=item B<create> [I<OPTIONS>] I<configfile>
The create subcommand requires a config file: see L<xldomain.cfg> for
full details of that file format and possible options.
I<configfile> can either be an absolute path to a file, or a relative
path to a file located in /etc/xen.
Create will return B<as soon> as the domain is started. This B<does
not> mean the guest OS in the domain has actually booted, or is
available for input.
B<OPTIONS>
=over 4
=item B<-q>, B<--quiet>
No console output.
=item B<-f=FILE>, B<--defconfig=FILE>
Use the given configuration file.
=item B<-n>, B<--dryrun>
Dry run - prints the resulting configuration in SXP but does not create
the domain.
=item B<-p>
Leave the domain paused after it is created.
=item B<-c>
Attach console to the domain as soon as it has started. This is
useful for determining issues with crashing domains.
=back
B<EXAMPLES>
=over 4
=item I<with config file>
xl create DebianLenny
This creates a domain with the file /etc/xen/DebianLenny, and returns as
soon as it is run.
=back
=item B<console> I<domain-id>
Attach to domain I<domain-id>'s console. If you've set up your domains to
have a traditional log in console this will look much like a normal
text log in screen.
Use the key combination Ctrl+] to detach the domain console.
=item B<vncviewer> [I<OPTIONS>] I<domain-id>
Attach to domain's VNC server, forking a vncviewer process.
B<OPTIONS>
=over 4
=item I<--autopass>
Pass VNC password to vncviewer via stdin.
=back
=item B<destroy> I<domain-id>
Immediately terminate the domain I<domain-id>. This doesn't give the
domain OS any chance to react, and is the equivalent of ripping the
power cord out on a physical machine. In most cases you will want to
use the B<shutdown> command instead.
=item B<domid> I<domain-name>
Converts a domain name to a domain id.
=item B<domname> I<domain-id>
Converts a domain id to a domain name.
=item B<rename> I<domain-id> I<new-name>
Change the domain name of I<domain-id> to I<new-name>.
=item B<dump-core> I<domain-id> [I<filename>]
Dumps the virtual machine's memory for the specified domain to the
I<filename> specified, without pausing the domain. The dump file will
be written to a distribution specific directory for dump files. Such
as: /var/lib/xen/dump or /var/xen/dump.
=item B<help> [I<--long>]
Displays the short help message (i.e. common commands).
The I<--long> option prints out the complete set of B<xl> subcommands,
grouped by function.
=item B<list> [I<OPTIONS>] [I<domain-id> ...]
Prints information about one or more domains. If no domains are
specified it prints out information about all domains.
B<OPTIONS>
=over 4
=item B<-l>, B<--long>
The output for B<xl list> is not the table view shown below, but
instead presents the data in SXP compatible format.
=item B<-Z>, B<--context>
Also prints the security labels.
=item B<-v>, B<--verbose>
Also prints the domain UUIDs, the shutdown reason and security labels.
=back
B<EXAMPLE>
An example format for the list is as follows:
Name ID Mem VCPUs State Time(s)
Domain-0 0 750 4 r----- 11794.3
win 1 1019 1 r----- 0.3
linux 2 2048 2 r----- 5624.2
Name is the name of the domain. ID the numeric domain id. Mem is the
desired amount of memory to allocate to the domain (although it may
not be the currently allocated amount). VCPUs is the number of
virtual CPUs allocated to the domain. State is the run state (see
below). Time is the total run time of the domain as accounted for by
Xen.
B<STATES>
The State field lists 6 states for a Xen domain, and which ones the
current domain is in.
=over 4
=item B<r - running>
The domain is currently running on a CPU.
=item B<b - blocked>
The domain is blocked, and not running or runnable. This can be caused
because the domain is waiting on IO (a traditional wait state) or has
gone to sleep because there was nothing else for it to do.
=item B<p - paused>
The domain has been paused, usually occurring through the administrator
running B<xl pause>. When in a paused state the domain will still
consume allocated resources like memory, but will not be eligible for
scheduling by the Xen hypervisor.
=item B<s - shutdown>
FIXME: Why would you ever see this state?
=item B<c - crashed>
The domain has crashed, which is always a violent ending. Usually
this state can only occur if the domain has been configured not to
restart on crash. See L<xldomain.cfg> for more info.
=item B<d - dying>
The domain is in process of dying, but hasn't completely shutdown or
crashed.
FIXME: Is this right?
=back
B<NOTES>
=over 4
The Time column is deceptive. Virtual IO (network and block devices)
used by domains requires coordination by Domain0, which means that
Domain0 is actually charged for much of the time that a DomainU is
doing IO. Use of this time value to determine relative utilizations
by domains is thus very suspect, as a high IO workload may show as
less utilized than a high CPU workload. Consider yourself warned.
=back
=item B<mem-max> I<domain-id> I<mem>
Specify the maximum amount of memory the domain is able to use, appending 't'
for terabytes, 'g' for gigabytes, 'm' for megabytes, 'k' for kilobytes and 'b'
for bytes.
The mem-max value may not correspond to the actual memory used in the
domain, as it may balloon down its memory to give more back to the OS.
=item B<mem-set> I<domain-id> I<mem>
Set the domain's used memory using the balloon driver; append 't' for
terabytes, 'g' for gigabytes, 'm' for megabytes, 'k' for kilobytes and 'b' for
bytes.
Because this operation requires cooperation from the domain operating
system, there is no guarantee that it will succeed. This command will
definitely not work unless the domain has the required paravirt
driver.
B<Warning:> There is no good way to know in advance how small of a
mem-set will make a domain unstable and cause it to crash. Be very
careful when using this command on running domains.
=item B<migrate> [I<OPTIONS>] I<domain-id> I<host>
Migrate a domain to another host machine. By default B<xl> relies on ssh as a
transport mechanism between the two hosts.
B<OPTIONS>
=over 4
=item B<-s> I<sshcommand>
Use <sshcommand> instead of ssh. String will be passed to sh. If empty, run
<host> instead of ssh <host> xl migrate-receive [-d -e].
=item B<-e>
On the new host, do not wait in the background (on <host>) for the death of the
domain.
=item B<-C> I<config>
Send <config> instead of config file from creation.
=back
=item B<pause> I<domain-id>
Pause a domain. When in a paused state the domain will still consume
allocated resources such as memory, but will not be eligible for
scheduling by the Xen hypervisor.
=item B<reboot> [I<OPTIONS>] I<domain-id>
Reboot a domain. This acts just as if the domain had the B<reboot>
command run from the console. The command returns as soon as it has
executed the reboot action, which may be significantly before the
domain actually reboots.
The behavior of what happens to a domain when it reboots is set by the
B<on_reboot> parameter of the xldomain.cfg file when the domain was
created.
=item B<restore> [I<OPTIONS>] [I<ConfigFile>] I<CheckpointFile>
Build a domain from an B<xl save> state file. See B<save> for more info.
B<OPTIONS>
=over 4
=item B<-p>
Do not unpause domain after restoring it.
=item B<-e>
Do not wait in the background for the death of the domain on the new host.
=item B<-d>
Enable debug messages.
=back
=item B<save> [I<OPTIONS>] I<domain-id> I<CheckpointFile> [I<ConfigFile>]
Saves a running domain to a state file so that it can be restored
later. Once saved, the domain will no longer be running on the
system, unless the -c option is used.
B<xl restore> restores from this checkpoint file.
Passing a config file argument allows the user to manually select the VM config
file used to create the domain.
=over 4
=item B<-c>
Leave domain running after creating the snapshot.
=back
=item B<shutdown> [I<OPTIONS>] I<domain-id>
Gracefully shuts down a domain. This coordinates with the domain OS
to perform graceful shutdown, so there is no guarantee that it will
succeed, and may take a variable length of time depending on what
services must be shutdown in the domain. The command returns
immediately after signally the domain unless that B<-w> flag is used.
The behavior of what happens to a domain when it reboots is set by the
B<on_shutdown> parameter of the xldomain.cfg file when the domain was
created.
B<OPTIONS>
=over 4
=item B<-w>
Wait for the domain to complete shutdown before returning.
=back
=item B<sysrq> I<domain-id> I<letter>
Send a I<Magic System Request> signal to the domain. For more
information on available magic sys req operations, see sysrq.txt in
your Linux Kernel sources.
=item B<unpause> I<domain-id>
Moves a domain out of the paused state. This will allow a previously
paused domain to now be eligible for scheduling by the Xen hypervisor.
=item B<vcpu-set> I<domain-id> I<vcpu-count>
Enables the I<vcpu-count> virtual CPUs for the domain in question.
Like mem-set, this command can only allocate up to the maximum virtual
CPU count configured at boot for the domain.
If the I<vcpu-count> is smaller than the current number of active
VCPUs, the highest number VCPUs will be hotplug removed. This may be
important for pinning purposes.
Attempting to set the VCPUs to a number larger than the initially
configured VCPU count is an error. Trying to set VCPUs to < 1 will be
quietly ignored.
Because this operation requires cooperation from the domain operating
system, there is no guarantee that it will succeed. This command will
not work with a full virt domain.
=item B<vcpu-list> [I<domain-id>]
Lists VCPU information for a specific domain. If no domain is
specified, VCPU information for all domains will be provided.
=item B<vcpu-pin> I<domain-id> I<vcpu> I<cpus>
Pins the VCPU to only run on the specific CPUs. The keyword
B<all> can be used to apply the I<cpus> list to all VCPUs in the
domain.
Normally VCPUs can float between available CPUs whenever Xen deems a
different run state is appropriate. Pinning can be used to restrict
this, by ensuring certain VCPUs can only run on certain physical
CPUs.
=item B<button-press> I<domain-id> I<button>
Indicate an ACPI button press to the domain. I<button> is may be 'power' or
'sleep'.
=item B<trigger> I<domain-id> I<nmi|reset|init|power|sleep> [I<VCPU>]
Send a trigger to a domain, where the trigger can be: nmi, reset, init, power
or sleep. Optionally a specific vcpu number can be passed as an argument.
=item B<getenforce>
Returns the current enforcing mode of the Flask Xen security module.
=item B<setenforce> I<1|0|Enforcing|Permissive>
Sets the current enforcing mode of the Flask Xen security module
=item B<loadpolicy> I<policyfile>
Loads a new policy int the Flask Xen security module.
=back
=head1 XEN HOST SUBCOMMANDS
=over 4
=item B<debug-keys> I<keys>
Send debug I<keys> to Xen.
=item B<dmesg> [B<-c>]
Reads the Xen message buffer, similar to dmesg on a Linux system. The
buffer contains informational, warning, and error messages created
during Xen's boot process. If you are having problems with Xen, this
is one of the first places to look as part of problem determination.
B<OPTIONS>
=over 4
=item B<-c>, B<--clear>
Clears Xen's message buffer.
=back
=item B<info> [B<-n>, B<--numa>]
Print information about the Xen host in I<name : value> format. When
reporting a Xen bug, please provide this information as part of the
bug report.
Sample output looks as follows (lines wrapped manually to make the man
page more readable):
host : talon
release : 2.6.12.6-xen0
version : #1 Mon Nov 14 14:26:26 EST 2005
machine : i686
nr_cpus : 2
nr_nodes : 1
cores_per_socket : 1
threads_per_core : 1
cpu_mhz : 696
hw_caps : 0383fbff:00000000:00000000:00000040
total_memory : 767
free_memory : 37
xen_major : 3
xen_minor : 0
xen_extra : -devel
xen_caps : xen-3.0-x86_32
xen_scheduler : credit
xen_pagesize : 4096
platform_params : virt_start=0xfc000000
xen_changeset : Mon Nov 14 18:13:38 2005 +0100
7793:090e44133d40
cc_compiler : gcc version 3.4.3 (Mandrakelinux
10.2 3.4.3-7mdk)
cc_compile_by : sdague
cc_compile_domain : (none)
cc_compile_date : Mon Nov 14 14:16:48 EST 2005
xend_config_format : 4
B<FIELDS>
Not all fields will be explained here, but some of the less obvious
ones deserve explanation:
=over 4
=item B<hw_caps>
A vector showing what hardware capabilities are supported by your
processor. This is equivalent to, though more cryptic, the flags
field in /proc/cpuinfo on a normal Linux machine.
=item B<free_memory>
Available memory (in MB) not allocated to Xen, or any other domains.
=item B<xen_caps>
The Xen version and architecture. Architecture values can be one of:
x86_32, x86_32p (i.e. PAE enabled), x86_64, ia64.
=item B<xen_changeset>
The Xen mercurial changeset id. Very useful for determining exactly
what version of code your Xen system was built from.
=back
B<OPTIONS>
=over 4
=item B<-n>, B<--numa>
List host NUMA topology information
=back
=item B<top>
Executes the B<xentop> command, which provides real time monitoring of
domains. Xentop is a curses interface, and reasonably self
explanatory.
=item B<uptime>
Prints the current uptime of the domains running.
=item B<pci-list-assignable-devices>
List all the assignable PCI devices.
=back
=head1 SCHEDULER SUBCOMMANDS
Xen ships with a number of domain schedulers, which can be set at boot
time with the B<sched=> parameter on the Xen command line. By
default B<credit> is used for scheduling.
=over 4
=item B<sched-credit> [ B<-d> I<domain-id> [ B<-w>[B<=>I<WEIGHT>] | B<-c>[B<=>I<CAP>] ] ]
Set credit scheduler parameters. The credit scheduler is a
proportional fair share CPU scheduler built from the ground up to be
work conserving on SMP hosts.
Each domain (including Domain0) is assigned a weight and a cap.
B<PARAMETERS>
=over 4
=item I<WEIGHT>
A domain with a weight of 512 will get twice as much CPU as a domain
with a weight of 256 on a contended host. Legal weights range from 1
to 65535 and the default is 256.
=item I<CAP>
The cap optionally fixes the maximum amount of CPU a domain will be
able to consume, even if the host system has idle CPU cycles. The cap
is expressed in percentage of one physical CPU: 100 is 1 physical CPU,
50 is half a CPU, 400 is 4 CPUs, etc. The default, 0, means there is
no upper cap.
=back
=back
=head1 CPUPOOLS COMMANDS
Xen can group the physical cpus of a server in cpu-pools. Each physical CPU is
assigned at most to one cpu-pool. Domains are each restricted to a single
cpu-pool. Scheduling does not cross cpu-pool boundaries, so each cpu-pool has
an own scheduler.
Physical cpus and domains can be moved from one pool to another only by an
explicit command.
=over 4
=item B<cpupool-create> [I<OPTIONS>] I<ConfigFile>
Create a cpu pool based an I<ConfigFile>.
B<OPTIONS>
=over 4
=item B<-f=FILE>, B<--defconfig=FILE>
Use the given configuration file.
=item B<-n>, B<--dryrun>
Dry run - prints the resulting configuration.
=back
=item B<cpupool-list> [I<-c|--cpus> I<cpu-pool>]
List CPU pools on the host.
If I<-c> is specified, B<xl> prints a list of CPUs used by I<cpu-pool>.
=item B<cpupool-destroy> I<cpu-pool>
Deactivates a cpu pool.
=item B<cpupool-rename> I<cpu-pool> <newname>
Renames a cpu pool to I<newname>.
=item B<cpupool-cpu-add> I<cpu-pool> I<cpu-nr|node-nr>
Adds a cpu or a numa node to a cpu pool.
=item B<cpupool-cpu-remove> I<cpu-nr|node-nr>
Removes a cpu or a numa node from a cpu pool.
=item B<cpupool-migrate> I<domain-id> I<cpu-pool>
Moves a domain into a cpu pool.
=item B<cpupool-numa-split>
Splits up the machine into one cpu pool per numa node.
=back
=head1 VIRTUAL DEVICE COMMANDS
Most virtual devices can be added and removed while guests are
running. The effect to the guest OS is much the same as any hotplug
event.
=head2 BLOCK DEVICES
=over 4
=item B<block-attach> I<domain-id> I<disc-spec-component(s)> ...
Create a new virtual block device. This will trigger a hotplug event
for the guest.
B<OPTIONS>
=over 4
=item I<domain-id>
The domain id of the guest domain that the device will be attached to.
=item I<disc-spec-component>
A disc specification in the same format used for the B<disk> variable in
the domain config file. See L<xldomain.cfg>.
=back
=item B<block-detach> I<domain-id> I<devid> [B<--force>]
Detach a domain's virtual block device. I<devid> may be the symbolic
name or the numeric device id given to the device by domain 0. You
will need to run B<xl block-list> to determine that number.
Detaching the device requires the cooperation of the domain. If the
domain fails to release the device (perhaps because the domain is hung
or is still using the device), the detach will fail. The B<--force>
parameter will forcefully detach the device, but may cause IO errors
in the domain.
=item B<block-list> I<domain-id>
List virtual block devices for a domain.
=item B<cd-insert> I<domain-id> I<VirtualDevice> I<be-dev>
Insert a cdrom into a guest domain's cd drive. Only works with HVM domains.
B<OPTIONS>
=over 4
=item I<VirtualDevice>
How the device should be presented to the guest domain; for example /dev/hdc.
=item I<be-dev>
the device in the backend domain (usually domain 0) to be exported; it can be a
path to a file (file://path/to/file.iso). See B<disk> in L<xldomain.cfg> for the
details.
=back
=item B<cd-eject> I<domain-id> I<VirtualDevice>
Eject a cdrom from a guest's cd drive. Only works with HVM domains.
I<VirtualDevice> is the cdrom device in the guest to eject.
=back
=head2 NETWORK DEVICES
=over 4
=item B<network-attach> I<domain-id> I<network-device>
Creates a new network device in the domain specified by I<domain-id>.
I<network-device> describes the device to attach, using the same format as the
B<vif> string in the domain config file. See L<xldomain.cfg> for the
description.
=item B<network-detach> I<domain-id> I<devid|mac>
Removes the network device from the domain specified by I<domain-id>.
I<devid> is the virtual interface device number within the domain
(i.e. the 3 in vif22.3). Alternatively the I<mac> address can be used to
select the virtual interface to detach.
=item B<network-list> I<domain-id>
List virtual network interfaces for a domain.
=back
=head2 PCI PASS-THROUGH
=over 4
=item B<pci-attach> I<domain-id> I<BDF>
Hot-plug a new pass-through pci device to the specified domain.
B<BDF> is the PCI Bus/Device/Function of the physical device to pass-through.
=item B<pci-detach> [I<-f>] I<domain-id> I<BDF>
Hot-unplug a previously assigned pci device from a domain. B<BDF> is the PCI
Bus/Device/Function of the physical device to be removed from the guest domain.
If B<-f> is specified, B<xl> is going to forcefully remove the device even
without guest's collaboration.
=item B<pci-list> I<domain-id>
List pass-through pci devices for a domain.
=back
=head1 SEE ALSO
B<xldomain.cfg>(5), B<xentop>(1)
=head1 AUTHOR
Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Vincent Hanquez <vincent.hanquez@eu.citrix.com>
Ian Jackson <ian.jackson@eu.citrix.com>
Ian Campbell <Ian.Campbell@citrix.com>
=head1 BUGS
Send bugs to xen-devel@lists.xensource.com.
Reference in new issue
Block a user
Blocking a user prevents them from interacting with repositories, such as opening or commenting on pull requests or issues. Learn more about blocking a user.