lttng-snapshot(1)
=================
+:revdate: 9 November 2018
NAME
Add a snapshot output:
[verse]
-*lttng* ['GENERAL OPTIONS'] *snapshot add-output* [option:--max-size='SIZE']
+*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *snapshot add-output* [option:--max-size='SIZE']
[option:--name='NAME'] [option:--session='SESSION']
(option:--ctrl-url='URL' option:--data-url='URL' | 'URL')
Remove a snapshot output:
[verse]
-*lttng* ['GENERAL OPTIONS'] *snapshot del-output* [option:--session='SESSION']
+*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *snapshot del-output* [option:--session='SESSION']
('ID' | 'NAME')
List current snapshot outputs:
[verse]
-*lttng* ['GENERAL OPTIONS'] *snapshot list-output* [option:--session='SESSION']
+*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *snapshot list-output* [option:--session='SESSION']
Take a snapshot:
[verse]
-*lttng* ['GENERAL OPTIONS'] *snapshot record* [option:--max-size='SIZE']
+*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *snapshot record* [option:--max-size='SIZE']
[option:--name='NAME'] [option:--session='SESSION']
(option:--ctrl-url='URL' option:--data-url='URL' | 'URL')
The tracing session should be created in _snapshot mode_ to make sure
taking snapshots is allowed. This is done at tracing session creation
-time using the linklttng:lttng-create(1) command.
+time using the man:lttng-create(1) command.
Note that, when a snapshot is taken, the sub-buffers are not cleared.
This means that different recorded snapshots may contain the same
A snapshot output can be added using the `add-output` action. The
output destination URL is set using either the 'URL' positional
argument, or both the option:--ctrl-url and option:--data-url options.
-See linklttng:lttng-create(1) to learn more about the URL format.
+See man:lttng-create(1) to learn more about the URL format.
A name can be assigned to an output when adding it using the
option:--name option. This name is part of the names of the
~~~~~~~~~~~~~~~~~
Taking a snapshot of the current tracing session is as easy as:
----------------------
-lttng snapshot record
----------------------
+[role="term"]
+----
+$ lttng snapshot record
+----
This writes the snapshot files to the configured output. It is possible
to use a custom, unregistered output at record time using the same
NOTE: Before taking a snapshot on a system with a high event throughput,
it is recommended to first run `lttng stop` (see
-linklttng:lttng-stop(1)). Otherwise, the snapshot could contain "holes",
+man:lttng-stop(1)). Otherwise, the snapshot could contain "holes",
the result of the tracers overwriting unconsumed trace packets during
the record operation. After the snapshot is recorded, the tracers can be
-started again with `lttng start` (see linklttng:lttng-start(1)).
+started again with `lttng start` (see man:lttng-start(1)).
include::common-cmd-options-head.txt[]
Target
~~~~~~
-option:-s, option:--session='SESSION'::
+option:-s 'SESSION', option:--session='SESSION'::
Take a snapshot of the sub-buffers of the channels contained in
the tracing session named 'SESSION' instead of the current
tracing session.
Snapshot output
~~~~~~~~~~~~~~~
-option:-C, option:--ctrl-url='URL'::
+option:-C 'URL', option:--ctrl-url='URL'::
Set control path URL to 'URL' (must use option:--data-url option
also).
-option:-D, option:--data-url='URL'::
+option:-D 'URL', option:--data-url='URL'::
Set data path URL to 'URL' (must use option:--ctrl-url option
also).
-option:-m, option:--max-size='SIZE'::
+option:-m 'SIZE', option:--max-size='SIZE'::
Limit the total size of all the snapshot files written when
recording a snapshot to 'SIZE' bytes. The `k` (kiB), `M` (MiB),
and `G` (GiB) suffixes are supported.
-option:-n, option:--name='NAME'::
+option:-n 'NAME', option:--name='NAME'::
Assign the name 'NAME' to the snapshot output.
SEE ALSO
--------
-linklttng:lttng-untrack(1),
-linklttng:lttng(1)
+man:lttng(1)