1 lttng-enable-rotation(1)
2 ========================
7 lttng-enable-rotation - Set a tracing session's rotation schedule
13 *lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *enable-rotation* (option:--timer='PERIOD' | option:--size='SIZE')
14 [option:--session='SESSION']
19 The `lttng enable-rotation` command sets a rotation schedule for the
20 current tracing session, or for the tracing session named 'SESSION' if
21 provided. See man:lttng-rotate(1) for more information about the
22 concepts of a tracing session _rotation_ and a _trace chunk_.
24 With the option:--timer option, the rotation schedule is set so that an
25 automatic rotation occurs at least every 'PERIOD' (microseconds without
28 With the option:--size option, the rotation schedule is set
29 so that an automatic rotation occurs every time the total size of the
30 flushed part of the current trace chunk is at least 'SIZE' (bytes
31 without a unit suffix).
33 For both option:--timer and option:--size options, LTTng checks the
34 schedule condition periodically using the monitor timers of the tracing
35 session's channels. This means that, with the option:--timer option, the
36 automatic rotation can occur when the elapsed time since the last
37 automatic rotation is greater than 'PERIOD', and with the option:--size
38 option, the automatic rotation can occur when the size of the flushed
39 part of the current trace chunk is greater than 'SIZE'. Therefore the
40 'PERIOD' and 'SIZE' arguments are approximations. See the
41 nloption:--monitor-timer option in man:lttng-enable-channel(1) for more
42 information about the monitor timer.
44 The naming convention of a trace chunk archive which an automatic
45 rotation creates is the same as with the immediate rotation command,
48 You can unset a rotation schedule with the man:lttng-disable-rotation(1)
51 See <<limitations,LIMITATIONS>> for important limitations regarding
55 include::common-cmd-options-head.txt[]
58 Rotation schedule condition
59 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
62 option:--size='SIZE'::
63 Set a rotation schedule so that an automatic rotation occurs every
64 time the total size of the flushed part of the current trace chunk
65 is at least 'SIZE' bytes. The `k` (kiB), `M` (MiB), and `G` (GiB)
66 suffixes are supported.
68 option:--timer='PERIOD'::
69 Set a rotation schedule so that an automatic rotation occurs at
70 least every 'PERIOD' microseconds. The `ms` (milliseconds), `s`
71 (seconds), `m` (minutes), and `h` (hours) suffixes are supported.
76 option:-s 'SESSION', option:--session='SESSION'::
77 Set a rotation schedule for the tracing session named 'SESSION'
78 instead of the current tracing session.
81 include::common-cmd-help-options.txt[]
87 The `lttng enable-rotation` command only works when:
89 * The tracing session is created in normal mode or in network streaming
90 mode (see man:lttng-create(1)).
92 * No channel was created with a configured trace file count or size
93 limit (see the nloption:--tracefile-size and
94 nloption:--tracefile-count options in man:lttng-enable-channel(1)).
96 For a given tracing session, LTTng only performs an automatic rotation
97 when no other rotation is currently happening.
100 include::common-cmd-footer.txt[]
106 man:lttng-disable-rotation(1),