{{tag>Brouillon Boot Kernel}} # Exemples paramètres noyau kernel Linux boot Voir aussi : * [[pb_disque_invisible_sur_hp_proliant_disque_invisible_lors_de_l_install_os_redhat7]] Kernel boot parameter ~~~bash cat /proc/cmdline ~~~ ## En cas de pb Voir : * https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html * https://help.ubuntu.com/community/BootOptions ~~~ noapic nolapic acpi=off nomodeset nodmraid ~~~ ~~~ edd=on ~~~ Désactiver Cloutinit ~~~ cloud-init=disabled ~~~ Désactiver la **mitigations** des CPU pour améliorer les performances au dépend de la sécurité Kernel 5.1.13 et sup ~~~ mitigations=off ~~~ Avant Kernel 5.1.13 `/etc/default/grub` ~~~bash GRUB_CMDLINE_LINUX="noibrs noibpb nopti nospectre_v2 nospectre_v1 l1tf=off nospec_store_bypass_disable no_stf_barrier mds=off tsx=on tsx_async_abort=off mitigations=off" ~~~ Retbleed ~~~ spectre_v2=ibrs retbleed=off ~~~ Voir https://access.redhat.com/solutions/retbleed ~~~ pnpbios=off noapic ~~~ Désactive partiellement KPTI (Kernel page-table isolation) \\ KPTI a été crée pour limiter l'impact de Meltdown ~~~ noibrs noibpb nopti #pti=off ~~~ Autres ~~~ini pci=noaer pcie_aspm=off ~~~ ### Fix boot errors Source : https://www.techradar.com/how-to/computing/how-to-fix-any-linux-problem-1322630 ~~~ noapic ~~~ ou ~~~ noapictimer, acpi=off ~~~ ou ~~~ acpi=force irqpoll pci=nommconf pci=nomsi ~~~ ~~~ splash=silent quiet showopts nvme_core.default_ps_max_latency_us=170000 crashkernel=192M,high crashkernel=72M,low intremap=no_x2apic_optout apic=verbose lapic irqfixup irqpoll i2c_i801.disable_features=0x10 hpet=disable initcall_blacklist=dw_i2c_init_driver nvme_core.default_ps_max_latency_us=200000 iwlmvm.power_scheme=1 iwlwifi.amsdu_size=3 lapic=notscdeadline acpi=rsdt pci=nocrs no_timer_check ~~~ Pb avec SSD BIOS : SATA sur **AHCI** à la place de **RAID** Ou change **RAID On** to **Disabled** (**Disable** : The SATA controllers are hidden). ~~~ nvme_load=YES ~~~ Source : https://www.dell.com/support/article/fr-fr/sln299303/chargement-d-ubuntu-sur-les-syst%C3%A8mes-%C3%A9quip%C3%A9s-de-disques-pcie-m2?lang=fr ## Debug ~~~bash loglevel=7 systemd.log_level=debug ~~~ ~~~ ignore_loglevel ~~~ Affiche tous les messages Peut être changé dynamiquement ## Linux Crashes, Reboots, ACPI and APIC Source : http://www.gilfether.com/linux-crashes-reboots-acpi-and-apic/357/ On single processor machines you can fully disable ACPI and APIC by passing kernel boot parameters: ~~~ noapic nolapic acpi=ht ~~~ On a dual core, quad core, or multiprocessor machine, you want to make sure you enable Local APIC. Local APIC has some kind of control over your Multiprocessor machine. If you shut off Local APIC on an multi-core or multiprocessor machine, you will only see one processor available. Use the following Kernel parameters: ~~~ noapic lapic acpi=ht ~~~ Exemple Oracle ~~~ numa=off transparent_hugepage=never clocksource=tsc ipv6.disable=1 audit=1 audit_backlog_limit=8192 ~~~ ## Exemples CloneZilla ~~~bash linux /live/vmlinuz boot=live union=overlay username=user config components noswap edd=on nomodeset nodmraid noeject locales=en_US.UTF-8 keyboard-layouts=NONE ocs_live_run="ocs-live-restore" ocs_live_extra_param="-e1 auto -e2 -c -r -j2 -scr -p true restoredisk IMAGES sda sdb" ocs_live_batch=yes vga=788 ip= net.ifnames=0 quiet nosplash i915.blacklist=yes radeonhd.blacklist=yes nouveau.blacklist=yes vmwgfx.enable_fbdev=1 ~~~ Autres ~~~ xdriver=vesa fastboot ~~~ UEFI ~~~bash video=efifb fbcon=rotate:1 ~~~ Désactive le chargement du microcode CPU ~~~ dis_ucode_ldr ~~~ Lenteur au boot à cause d'un maque d'entropie ~~~ini random.trust_cpu=on ~~~ Voir https://daniel-lange.com/archives/152-hello-buster.html Voir KVM : https://www.redhat.com/en/blog/red-hat-enterprise-linux-virtual-machines-access-random-numbers-made-easy ~~~bash memmap=512M\$1024M ~~~ `/etc/default/grub` ~~~bash GRUB_CMDLINE_LINUX_DEFAULT="quiet memmap=512M\\\$1024M" ~~~ ## Autres ~~~ini force_latency=cstate.id:1|3 force_latency=1 ~~~