CentOS8 CheatSheet fuer System Administratoren

1 SOS Report (Log Bundle)

This collects a log bundle which can be used for later debugging and analyzing.
Start this BEFORE you try to repair or change something, as well do not forget to snapshot/backup System/Application before debugging.

dnf -y install sos
sosreport
cp -av /var/tmp/sosreport* /root/

2 Events

2.1 Journal

• Follow all journal logs

journalctl -af

• Follow all journal logs with severity error or higher

journalctl --priority err --catalog --boot --follow

2.2 Log Files

• tail all currently open text files

lsof -F | sed '/^n\//!d;s/^n//;s/ .*//' | sort -u | xargs file | grep ' text$' | cut -d: -f1 | xargs tail -fn0

• tail all files under /var/log

tail -f -n0 /var/log/* /var/log/*/*

3 CentOS 8 Stream migration

CentOS8 will be discontinued by the Red Hat team. All the effort will go into CentOS Stream operating System which is a rolling release of CentOS.
You can directly migrate a CentOS8 into a CentOS8 Stream in place:

dnf install centos-release-stream
dnf distro-sync
cat /etc/centos-release
reboot