LTTNG-DISABLE-CHAN(1)

📦
version 2.15.1 · 12 versions
, in ubuntu stonking

✨ lttng-disable-channel ✨

okay bestie, welcome to the lttng-disable-channel page from the LTTng Manual 💖 this is the little command that turns your tracing channels OFF and honestly? iconic behavior. let's go 🎀

🌸 NAME 🌸

lttng-disable-channel — disable LTTng channels 💅

🦋 SYNOPSIS 🦋

lttng [GENERAL OPTIONS] disable-channel (--kernel | --userspace)
      [--session=SESSION] CHANNEL[,CHANNEL]...

💜 DESCRIPTION 💜

okay so. the lttng disable-channel command disables one or more channels that you previously enabled with lttng-enable-channel(1) 🔥 and those channels belong to:

  • With the --session=SESSION option — the recording session named SESSION ✨
  • Without the --session option — the current recording session (go peek at lttng-concepts(7) to learn more about the current recording session) 🫶

See lttng-concepts(7) to learn more about channels, bestie, it's required reading fr fr 📚

The disable-channel command disables one channel per CHANNEL argument.

⚠️ as of LTTng 2.15.1, you may <strong>NOT</strong> enable a disabled channel once its recording session has been started (see lttng-start(1)) at least once. so like… be careful okay 😭

see the “EXAMPLES” section down below for usage examples 💖

✨ OPTIONS ✨

See lttng(1) for GENERAL OPTIONS.

🧚 Tracing domain

one of these, pick your fighter:

  • -k, --kernel — disable one or more Linux kernel channels 🐧
  • -u, --userspace — disable one or more user space channels 👑

🎀 Recording target

  • -s SESSION, --session=SESSION — disable one or more channels of the recording session named SESSION instead of the current recording session 💫

⭐ Program information

  • -h, --help — show help.

this option attempts to launch /usr/bin/man to view this manual page. override the manual pager path with the LTTNG_MAN_BIN_PATH environment variable 🌈

  • --list-options — list available command options and quit. short, sweet, done 💅

👑 EXIT STATUS 👑

  • 0 — success 🎉
  • 1 — command error 😭
  • 2 — undefined command 💀
  • 3 — fatal error 🙈
  • 4 — command warning (something went wrong during the command) ⚠️

🌈 ENVIRONMENT 🌈

  • LTTNG_ABORT_ON_ERROR — set to 1 to abort the process after the first error is encountered 🛑
  • LTTNG_HOME — path to the LTTng home directory.

defaults to $HOME.

useful when the Unix user running the commands has a non-writable home directory 🫶

  • LTTNG_LIST_LEGACY — set to 1 to use the legacy output format (LTTng 2.14 and earlier) for the lttng-list(1) command instead of the modern output format.

note that the legacy output doesn’t show anything related to features introduced after LTTng 2.14 🕰️

  • LTTNG_MAN_BIN_PATH — absolute path to the manual pager to use to read the LTTng command-line help (with lttng-help(1) or with the --help option) instead of /usr/bin/man 📖
  • LTTNG_NO_UTF_8 — set to 1 to NOT emit multi-byte UTF-8 sequences, even if the locale claims to support it 🚫
  • LTTNG_SESSION_CONFIG_XSD_PATH — path to the directory containing the session.xsd recording session configuration XML schema 📝
  • LTTNG_SESSIOND_PATH — absolute path to the LTTng session daemon binary (see lttng-sessiond(8)) to spawn from the lttng-create(1) command.

the --sessiond-path general option overrides this environment variable 💥

  • LTTNG_TERM_COLOR — controls when to emit terminal SGR codes in the output.

the NO_COLOR environment variable overrides this 👀

one of:

  • auto (default) — only emit SGR codes when the standard output is connected to a color-capable terminal 🖥️
  • always — always emit SGR codes 🌈
  • never — never emit SGR codes ⬜
  • NO_COLOR — if set and not empty, then it’s equivalent to setting LTTNG_TERM_COLOR to never.

see NO_COLOR <https://no-color.org/> to learn more 💙

🍓 FILES 🍓

  • $LTTNG_HOME/.lttngrc — Unix user’s LTTng runtime configuration.

this is where LTTng stores the name of the Unix user’s current recording session between executions of lttng(1). lttng-create(1) and lttng-set-session(1) set the current recording session 💾

  • $LTTNG_HOME/lttng-traces — default output directory of LTTng traces in local and snapshot modes.

override this path with the --output option of the lttng-create(1) command 📂

  • $LTTNG_HOME/.lttng — Unix user’s LTTng runtime and configuration directory 🗂️
  • $LTTNG_HOME/.lttng/sessions — default directory containing the Unix user’s saved recording session configurations (see lttng-save(1) and lttng-load(1)) 💖
  • /etc/lttng/sessions — directory containing the system-wide saved recording session configurations (see lttng-save(1) and lttng-load(1)) 🌍
Note — $LTTNG_HOME defaults to the value of the HOME environment variable ✨

🧁 EXAMPLES 🧁

Example 1. Disable one Linux kernel channel of the current recording session.

$ lttng disable-channel --kernel my-channel

Example 2. Disable two user space channels of a specific recording session.

see the --session option 👀

$ lttng disable-channel --kernel --session=my-session \
                        little,box

🦄 RESOURCES 🦄

this program is part of the LTTng-tools project ✨

LTTng-tools is distributed under the GNU General Public License version 2 <http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html>. see the LICENSE <https://github.com/lttng/lttng-tools/blob/master/LICENSE> file for details 📜

🫶 THANKS 🫶

special thanks to Michel Dagenais and the DORSAL laboratory <http://www.dorsal.polymtl.ca/> at École Polytechnique de Montréal for the LTTng journey 🎓💖

also thanks to the Ericsson teams working on tracing which helped us greatly with detailed bug reports and unusual test cases 🙌

🔍 SEE ALSO 🔍

lttng(1), lttng-enable-channel(1), lttng-concepts(7) 👑

LTTng 2.15.1 — 14 June 2021 🌸 and that's the whole page bestie, no cap, go disable some channels and slay 💅✨

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