The Kernel's Messages

What the kernel is saying

The kernel — the core of the operating system that talks to the hardware — keeps its own running log: disks appearing, drivers loading, things going wrong at a low level. dmesg prints it; -T shows human-readable timestamps:

sudo dmesg -T | tail -n 10

In the terminal

student@vulntech:~$ sudo dmesg -T | tail -n 10
[sudo] password for student:
[Sun Oct 18 08:22:41 2026] systemd-journald[182]: Received client request to rotate journal, rotating.
[Sun Oct 18 08:22:41 2026] systemd-journald[182]: Vacuuming done, freed 0B of archived journals from /run/log/journal/af6a62848ea543edba71b458aa422ff7.
[Sun Oct 18 08:23:20 2026] watchdog: BUG: soft lockup - CPU#0 stuck for 32s! [vt-agent:218]
[Sun Oct 18 08:23:20 2026] Modules linked in: tcp_diag udp_diag inet_diag bochs drm_vram_helper drm_ttm_helper ttm drm_kms_helper fb_sys_fops syscopyarea pcspkr sysfillrect sysimgblt joydev evdev serio_raw sg fuse drm efi_pstore dm_mod configfs ip_tables x_tables autofs4 loop 9p fscache netfs sr_mod cdrom ata_generic 9pnet_virtio ata_piix 9pnet libata scsi_mod virtio_pci virtio_pci_legacy_dev virtio_pci_modern_dev ne2k_pci psmouse virtio virtio_ring 8390 scsi_common
[Sun Oct 18 08:23:20 2026] CPU: 0 PID: 218 Comm: vt-agent Not tainted 6.1.0-54-686 #1  Debian 6.1.190-1
[Sun Oct 18 08:23:20 2026] EIP: 0x4e6471
[Sun Oct 18 08:23:20 2026] Code: ff 83 c4 10 85 f6 0f 84 8a fe ff ff f6 44 24 58 03 0f 85 81 fe ff ff e9 57 fe ff ff 8d 74 26 00 90 31 d2 89 f8 e8 8f 81 fe ff <89> c6 83 ec 0c 57 e8 a4 fd fa ff 83 c4 10 e9 5b fe ff ff 8d 74 26
[Sun Oct 18 08:23:20 2026] EAX: 01c56480 EBX: 005c8aa4 ECX: 01c5a6bb EDX: 01c564db
[Sun Oct 18 08:23:20 2026] ESI: 01c5a1f0 EDI: 01c5a660 EBP: 01c5a400 ESP: bfb6ff50
[Sun Oct 18 08:23:20 2026] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b EFLAGS: 00000286

The same messages in the journal: -k

systemd also files the kernel's messages in the journal, so sudo journalctl -k shows the same thing with all of sudo journalctl's filters available:

sudo journalctl -k --no-pager -n 10

In the terminal

student@vulntech:~$ sudo journalctl -k --no-pager -n 10
[sudo] password for student:
Oct 18 04:45:21 vulntech systemd-journald[182]: Received client request to rotate journal, rotating.
Oct 18 04:45:21 vulntech systemd-journald[182]: Vacuuming done, freed 0B of archived journals from /run/log/journal/af6a62848ea543edba71b458aa422ff7.
Oct 18 04:46:03 vulntech kernel: watchdog: BUG: soft lockup - CPU#0 stuck for 34s! [vt-agent:218]
Oct 18 04:46:03 vulntech kernel: Modules linked in: tcp_diag udp_diag inet_diag bochs drm_vram_helper drm_ttm_helper ttm drm_kms_helper fb_sys_fops syscopyarea pcspkr sysfillrect sysimgblt joydev evdev serio_raw sg fuse drm efi_pstore dm_mod configfs ip_tables x_tables autofs4 loop 9p fscache netfs sr_mod cdrom ata_generic 9pnet_virtio ata_piix 9pnet libata scsi_mod virtio_pci virtio_pci_legacy_dev virtio_pci_modern_dev ne2k_pci psmouse virtio virtio_ring 8390 scsi_common
Oct 18 04:46:03 vulntech kernel: CPU: 0 PID: 218 Comm: vt-agent Not tainted 6.1.0-54-686 #1  Debian 6.1.190-1
Oct 18 04:46:03 vulntech kernel: EIP: 0x4e6471
Oct 18 04:46:03 vulntech kernel: Code: ff 83 c4 10 85 f6 0f 84 8a fe ff ff f6 44 24 58 03 0f 85 81 fe ff ff e9 57 fe ff ff 8d 74 26 00 90 31 d2 89 f8 e8 8f 81 fe ff <89> c6 83 ec 0c 57 e8 a4 fd fa ff 83 c4 10 e9 5b fe ff ff 8d 74 26
Oct 18 04:46:03 vulntech kernel: EAX: 01c56480 EBX: 005c8aa4 ECX: 01c5a6bb EDX: 01c564db
Oct 18 04:46:03 vulntech kernel: ESI: 01c5a1f0 EDI: 01c5a660 EBP: 01c5a400 ESP: bfb6ff50
Oct 18 04:46:03 vulntech kernel: DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b EFLAGS: 00000286

Tip: Kernel messages are where you look when hardware misbehaves — a disk with errors, a device that won't initialise. dmesg -T -l err,warn narrows dmesg to problems.

Remember: The kernel keeps a log of hardware and driver messages. Read it with dmesg (-T for readable times) or sudo journalctl -k.