Log rotation and retention

Articles

• journalctl — reading the systemd journal — Command for reading the systemd journal with service, time, and other filters.
• Log rotation with logrotate — Keeping logs from filling the disk — rotation, compression, retention, checking configs.
• lsof — open files and ports of processes — lsof shows which process holds a file, a port, or a deleted file that is still open.
• Disk space: df, du, inode — Where the space and inodes went — df, du, finding large files, pitfalls.
• tail — the last lines and following a log — The tail command prints the end of a file, and with -f it keeps showing new lines as they are appended to a log.