Mise à jour : Debian 9.3
Les exemples ci-dessous sont réalisés à partir du même journal, sur un système fonctionnant de façon satisfaisante.
Niveaux de journalisation possibles (priorités) :
emerg - le système est inutilisable
alert - il faut agir immédiatement
crit - conditions critiques
err - conditions d'erreur
warn - conditions d'avertissement
notice - condition normale mais significative
info - information
debug - messages du niveau de débogage
Exemple : Erreurs significatives
# dmesg -k -l "emerg,alert,crit,err"
[ 740.059628] [drm:intel_pipe_update_end [i915]] *ERROR* Atomic update failure on pipe A (start=44573 end=44574) time 205 us, min 894, max 899, scanline start 885, end 902
[ 822.035856] [drm:intel_pipe_update_end [i915]] *ERROR* Atomic update failure on pipe A (start=49476 end=49477) time 287 us, min 894, max 899, scanline start 876, end 902
Exemple : Avertissements
# dmesg -k -l "warn"
[ 0.014607] ENERGY_PERF_BIAS: Set to 'normal', was 'performance'
[ 0.014607] ENERGY_PERF_BIAS: View and update with x86_energy_perf_policy(8)
[ 0.380001] mtrr: your CPUs had inconsistent variable MTRR settings
[ 0.798427] pci 0000:05:00.0: [Firmware Bug]: VPD access disabled
[ 2.322581] iwlwifi 0000:03:00.0: can't disable ASPM; OS doesn't have ASPM control
[ 2.737456] uvcvideo 1-1.2:1.0: Entity type for entity Extension 3 was not initialized!
[ 2.737459] uvcvideo 1-1.2:1.0: Entity type for entity Processing 2 was not initialized!
[ 2.737461] uvcvideo 1-1.2:1.0: Entity type for entity Camera 1 was not initialized!
[ 3.344486] bbswitch: loading out-of-tree module taints kernel.
[ 3.344754] ACPI Warning: \_SB.PCI0.PEG0.GFX0._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20160831/nsarguments-95)
[ 3.346768] ACPI Warning: \_SB.PCI0.PEG0.GFX0._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20160831/nsarguments-95)
[ 3.723951] VBoxNetFlt: Successfully started.
[ 3.727031] VBoxNetAdp: Successfully started.
[ 3.731315] VBoxPciLinuxInit
Exemple :
# dmesg |grep -iE "warn|fail|miss|error|conflict|wrong"
[ 1.295226] fjes: module verification failed: signature and/or required key missing - tainting kernel
[ 2.408192] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro
[ 3.344754] ACPI Warning: \_SB.PCI0.PEG0.GFX0._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20160831/nsarguments-95)
[ 3.346768] ACPI Warning: \_SB.PCI0.PEG0.GFX0._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20160831/nsarguments-95)
[ 740.059628] [drm:intel_pipe_update_end [i915]] *ERROR* Atomic update failure on pipe A (start=44573 end=44574) time 205 us, min 894, max 899, scanline start 885, end 902
[ 822.035856] [drm:intel_pipe_update_end [i915]] *ERROR* Atomic update failure on pipe A (start=49476 end=49477) time 287 us, min 894, max 899, scanline start 876, end 902
A noter que la ligne numéro 2 n'est pas un message d'erreur, mais indique les conditions de montage de la partition en cas d'erreur.