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https://github.com/clearlinux/clear-linux-documentation.git
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alexjch
70 lines
1.8 KiB
Plaintext
70 lines
1.8 KiB
Plaintext
.. _kernel-boot-msg:
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Capture Kernel Boot Messages in the Journal
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###########################################
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By default |CL| does not capture kernel boot messages in the journal logs,
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where they're reported as "Missed" messages. This design decision was made
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to provide a faster boot performance. On the other hand, if you wish to
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see the messages, follow this guide.
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Here's an example a journal log with "Missed" messages:
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.. code-block:: console
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:linenos:
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:emphasize-lines: 4
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-- Reboot --
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Apr 10 19:55:43 kernel systemd-journald[300]: Journal started
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Apr 10 19:55:43 kernel systemd-journald[300]: Runtime Journal (/run/log/journal/d01862ca79d1064ea379cd715cfdd53a) is 5.8M, max 47.0M, 41.1M free.
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Apr 10 19:55:43 kernel systemd-journald[300]: Missed 2233 kernel messages
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Apr 10 19:55:43 kernel systemd[1]: Started Journal Service.
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.. contents::
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:local:
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:depth: 1
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Prerequisites
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*************
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* `systemd-journald` version 245 and higher
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Enable journaling of kernel boot messages
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*****************************************
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#. Open a terminal window.
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#. Create a base journald configuration file.
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.. code-block:: bash
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sudo mkdir -p /etc/systemd/journald.conf.d
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sudo cp /usr/lib/systemd/journald.conf.d/clear.conf /etc/systemd/journald.conf.d/
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#. Append :command:`BootKMsg=true` to it.
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.. code-block:: bash
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echo "BootKMsg=true" | sudo tee -a /etc/systemd/journald.conf.d/clear.conf
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#. Reboot.
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.. tip::
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If you need to increase the kernel buffer length (for example, 1M), do this:
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.. code-block:: bash
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sudo mkdir -p /etc/kernel/cmdline.d/
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echo "log_buf_len=1M" | sudo tee /etc/kernel/cmdline.d/log_buf_len.conf
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sudo clr-boot-manager update
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Alternative
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***********
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An alternative is to use :command:`dmesg`.
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.. code-block:: bash
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sudo dmesg
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