doc/man/lttng-enable-rotation.1.txt

   1 lttng-enable-rotation(1)
   2 ========================
   3
   4
   5 NAME
   6 ----
   7 lttng-enable-rotation - Set a tracing session's rotation schedule
   8
   9
  10 SYNOPSIS
  11 --------
  12 [verse]
  13 *lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *enable-rotation* (option:--timer='PERIOD' | option:--size='SIZE')
  14       [option:--session='SESSION']
  15
  16
  17 DESCRIPTION
  18 -----------
  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_.
  23
  24 With the option:--timer option, the rotation schedule is set so that an
  25 automatic rotation occurs at least every 'PERIOD' (microseconds without
  26 a unit suffix).
  27
  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).
  32
  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.
  43
  44 The naming convention of a trace chunk archive which an automatic
  45 rotation creates is the same as with the immediate rotation command,
  46 man:lttng-rotate(1).
  47
  48 You can unset a rotation schedule with the man:lttng-disable-rotation(1)
  49 command.
  50
  51 See <<limitations,LIMITATIONS>> for important limitations regarding
  52 this command.
  53
  54
  55 include::common-cmd-options-head.txt[]
  56
  57
  58 Rotation schedule condition
  59 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
  60 One of:
  61
  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.
  67
  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.
  72
  73
  74 Target
  75 ~~~~~~
  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.
  79
  80
  81 include::common-cmd-help-options.txt[]
  82
  83
  84 [[limitations]]
  85 LIMITATIONS
  86 -----------
  87 The `lttng enable-rotation` command only works when:
  88
  89 * The tracing session is created in normal mode or in network streaming
  90   mode (see man:lttng-create(1)).
  91
  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)).
  95
  96 For a given tracing session, LTTng only performs an automatic rotation
  97 when no other rotation is currently happening.
  98
  99
 100 include::common-cmd-footer.txt[]
 101
 102
 103 SEE ALSO
 104 --------
 105 man:lttng-rotate(1),
 106 man:lttng-disable-rotation(1),
 107 man:lttng(1)