doc/man/lttng-regenerate.1.txt

   1 lttng-regenerate(1)
   2 ===================
   3 :revdate: 18 January 2018
   4
   5
   6 NAME
   7 ----
   8 lttng-regenerate - Manage an LTTng tracing session's data regeneration
   9
  10
  11 SYNOPSIS
  12 --------
  13 Regenerate the metadata of a session:
  14
  15 [verse]
  16 *lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *regenerate metadata* [option:--session='SESSION']
  17
  18 Regenerate the state dump of a session:
  19
  20 [verse]
  21 *lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *regenerate statedump* [option:--session='SESSION']
  22
  23 DESCRIPTION
  24 -----------
  25 The `lttng regenerate` command regenerates specific data of a tracing session.
  26
  27 As of this version, the `metadata` and `statedump` actions are
  28 available.
  29
  30
  31 Regenerating a tracing session's metadata
  32 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  33 The `lttng regenerate metadata` action can be used to resample the offset
  34 between the system's monotonic clock and the wall-clock time.
  35
  36 This action is meant to be used to resample the wall-clock time following a
  37 major link:https://en.wikipedia.org/wiki/Network_Time_Protocol[NTP] correction.
  38 As such, a system booting with an incorrect wall time can be traced before its
  39 wall time is NTP-corrected. Regenerating the tracing session's metadata ensures
  40 that trace viewers can accurately determine the events time relative to Unix
  41 Epoch.
  42
  43 If you use man:lttng-rotate(1) or man:lttng-enable-rotation(1) to make
  44 tracing session rotations, this action regenerates the current and
  45 next trace chunks's metadata files.
  46
  47
  48 Regenerating a tracing session's state dump
  49 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  50 The `lttng regenerate statedump` action can be used to collect up-to-date state
  51 dump information during the tracing session. This is particularly useful in
  52 snapshot (see man:lttng-snapshot(1)) or trace file rotation (see
  53 man:lttng-enable-channel(1)) modes where the state dump information may be
  54 lost.
  55
  56
  57 include::common-cmd-options-head.txt[]
  58
  59
  60 option:-s 'SESSION', option:--session='SESSION'::
  61     Regenerate the data of the tracing session named 'SESSION'
  62     instead of the current tracing session.
  63
  64
  65 include::common-cmd-help-options.txt[]
  66
  67
  68 LIMITATIONS
  69 -----------
  70 The `lttng regenerate metadata` command can only be used on kernel and
  71 user space tracing sessions (using per-user buffering), in non-live
  72 mode.
  73
  74 See man:lttng-enable-channel(1) for more information about
  75 buffering schemes and man:lttng-create(1) for more information
  76 about the different tracing session modes.
  77
  78
  79 include::common-cmd-footer.txt[]
  80
  81
  82 SEE ALSO
  83 --------
  84 man:lttng(1)