Reading and Configuring System Logs (journalctl)

Created by Michael Lister, Modified on Mon, 9 Dec, 2024 at 10:40 AM by Michael Lister

This guide will show you how to read the system logs from a Raspberry Pi running Raspbian

Configuring Persistent System Logs

To allow for the logs in their entirety to be kept between boots, persistent logging needs to be enabled:

1. Open Terminal

2. Type:

sudo nano /etc/systemd/journald.conf

3. This will open a text editor within the terminal to edit the journal config file

Using the down arrow key scroll down to the [Journal] area

4. locate the "Storage=" option

Change it's value to "persistent"

5. Press CTRL + X

6. Press Y to save changes

7. Press ENTER to apply

1. Open Terminal

2 Type:

journalctl -b

3. The log for the current log will then be displayed within the terminal

Use Page Up/Down to scroll through the log

1. Open Terminal

2. Type:

journalctl --list-boots

3. A list of log files will be displayed, one is created after each boot

Along with the date/time of the first & last entry

You can make a note of the Index value or Boot ID to view the log later

Using the info from the boot list in the step above, you can view a log from a previous boot

1. Open Terminal

2. Type:

journalctl -b -X

Where X is the index of the log, as per the boot list

e.g. journalctl - b -1 will show the log from the previous boot, instead of the current one