Hi all guys and girls! I wanted to ask you what kind of switches for journalctl to use in order to have insight into possible failures. Using journlactl -b, I noticed quite a few errors, including the one about the data leakage by a bug in the processor. I disabled HyperThreading and quite a few of the errors disappeared, as well as the stalling during shutdown no longer happens. Is it possible to force journald to retain entries from earlier? Now only those from the current time are available. Thanks for your interest!
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
6 Likes
So I was wrong. The log list for the boot is 6 days so far. There is something to learn. I sincerely thank you!
1 Like
Let the good times roll!
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