DEBUG
Check for errors
journalctl -p3 -xb
Hardware boot stopping errors
journalctl -p3 -kxb
sudo dmesg -l "err,warn"
Failed services
systemctl --failed
XORG
Xorg logfiles are located in /var/log of the form Xorg.0.log, 0 being the display number.
Current session
grep -iE "\(EE\)|\(WW\)|error|failed" "/var/log/Xorg.0.log"
Previous successful session
grep -iE "\(EE\)|\(WW\)|error|failed" "/var/log/Xorg.0.log.old"
JOURNAL
Configs
/etc/systemd/journald.conf
/etc/systemd/journald.conf.d/*.conf
Manuals
man journalctl
man journald.conf
Journals summary size
du -sh "/var/log/journal"
If the journal is persistent (non-volatile), it’s size limit is set to a default value of 10% of the size of the underlying file system but capped at 4 GiB. For example, with /var/log/journal located on a 50 GiB partition, it would max at 4 GiB.
Supported log levels (priorities) for -p
| № | Level | Description |
|---|---|---|
| 0 | emerg | system is unusable |
| 1 | alert | action must be taken immediately |
| 2 | crit | critical conditions |
| 3 | err | error conditions |
| 4 | warn | warning conditions |
| 5 | notice | normal but significant condition |
| 6 | info | informational |
| 7 | debug | debug-level messages |
Previous boot
journalctl -p3 -xb -1
List available boots
journalctl --list-boots
Range of error priority
journalctl -p3..1
Live log, follow new messages
journalctl -p3 -f
New lines first
journalctl -p3 -r
Since 20 minutes ago
journalctl -p3 --since "20 min ago"
Since date (and optional time)
journalctl -p3 --since "2021-08-30 18:17:16"
Specific time period
journalctl -p3 --since="2021-08-15" --until="2021-10-16 23:59:59"
Specific binary
journalctl "/usr/lib/systemd/systemd"
Specific process
journalctl _PID=1
Specific device
journalctl /dev/sdc