dmesg

Read kernel ring buffer messages (hardware, boot, errors)

dmesg shows kernel messages: hardware detection at boot, driver errors, OOM kill events, filesystem errors. dmesg -T shows human-readable timestamps. dmesg | grep -i error filters for errors. Essential for diagnosing kernel-level issues.

Example

$ dmesg | tail -5
[12345.678] EXT4-fs (sda1): mounted filesystem
[12346.789] NET: Registered PF_INET6 protocol family

Tip: Type it yourself in the terminal below - reading is not the same as doing.