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