Swapping Kernels?

darkcity · 15 November 2022 16:36

When is the error message “/etc/default/grub: line 6: grub: command not found” displayed, when you boot up?

What is line 6 of /etc/default/grub ?

leledumbo · 15 November 2022 18:11

Recent kernels should not need RT anymore, only threadirqs kernel command line required. Of course your actual needs might be tougher that you actually need a RT kernel, just trying to give a suggestion. Ardour and Guitarix run responsively with ~2ms latency on my system.

pax-eterna · 15 November 2022 18:13

Sorry, just realized in my post above there was a typo: the command I MEANT was sudo update-grub not edit-grub (I changed it)

So this is what I entered and the result:
sudo update-grub
/etc/default/grub: line 6: grub: command not found

darkcity · 15 November 2022 18:15

What is line 6 of /etc/default/grub ?

pax-eterna · 15 November 2022 18:16

yes I thought I should post that:

GRUB_CMDLINE_LINUX="cpufreq.default_governor=performance threadirqs"Generating grub configuration file …

darkcity · 15 November 2022 18:20

I’m guess that it should only read what is within the quote marks

GRUB_CMDLINE_LINUX="cpufreq.default_governor=performance threadirqs"

for reference mine is just empty quotes

GRUB_CMDLINE_LINUX=""

pax-eterna · 15 November 2022 18:27

FWIW, this is the complete readout:

GRUB_DEFAULT=saved
GRUB_TIMEOUT=5
GRUB_TIMEOUT_STYLE=menu
GRUB_DISTRIBUTOR=“Manjaro”
GRUB_CMDLINE_LINUX_DEFAULT=“quiet apparmor=1 security=apparmor udev.log_priority=3”
GRUB_CMDLINE_LINUX="cpufreq.default_governor=performance threadirqs"Generating grub configuration file …
GRUB_DISABLE_OS_PROBER=false
Found theme: /usr/share/grub/themes/manjaro/theme.txt
Found linux image: /boot/vmlinuz-5.19-rt-x86_64
Found initrd image: /boot/intel-ucode.img /boot/initramfs-5.19-rt-x86_64.img
Found initrd fallback image: /boot/initramfs-5.19-rt-x86_64-fallback.img
fgrep: warning: fgrep is obsolescent; using grep -F
Warning: os-prober will be executed to detect other bootable partitions.
Its output will be used to detect bootable binaries on them and create new boot entries.
Adding boot menu entry for UEFI Firmware Settings …
Found memtest86+ image: /boot/memtest86+/memtest.bin

darkcity · 15 November 2022 18:40

it looks like /etc/default/grub has got mixed up some output messages from the terminal.

Could you have pressed the middle mouse button and pasted output from the terminal in there?

Do you have a backup for that file before editing?

here is mine:

GRUB_DEFAULT=saved
GRUB_TIMEOUT_STYLE=menu
GRUB_TIMEOUT=6
GRUB_DISTRIBUTOR="Manjaro"
GRUB_CMDLINE_LINUX_DEFAULT="resume=UUID=1234 udev.log_priority=3"
GRUB_CMDLINE_LINUX=""

# If you want to enable the save default function, uncomment the following
# line, and set GRUB_DEFAULT to saved.
GRUB_SAVEDEFAULT=true

# Preload both GPT and MBR modules so that they are not missed
GRUB_PRELOAD_MODULES="part_gpt part_msdos"

# Uncomment to enable booting from LUKS encrypted devices
#GRUB_ENABLE_CRYPTODISK=y

# Uncomment to use basic console
GRUB_TERMINAL_INPUT=console

# Uncomment to disable graphical terminal
#GRUB_TERMINAL_OUTPUT=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command 'videoinfo'
GRUB_GFXMODE=1600x900

# Uncomment to allow the kernel use the same resolution used by grub
GRUB_GFXPAYLOAD_LINUX=1600x900

# Uncomment if you want GRUB to pass to the Linux kernel the old parameter
# format "root=/dev/xxx" instead of "root=/dev/disk/by-uuid/xxx"
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
GRUB_DISABLE_RECOVERY=true

# Uncomment this option to enable os-prober execution in the grub-mkconfig command
GRUB_DISABLE_OS_PROBER=false

# Uncomment and set to the desired menu colors.  Used by normal and wallpaper
# modes only.  Entries specified as foreground/background.
GRUB_COLOR_NORMAL="light-gray/black"
GRUB_COLOR_HIGHLIGHT="green/black"

# Uncomment one of them for the gfx desired, a image background or a gfxtheme
#GRUB_BACKGROUND="/usr/share/grub/background.png"
GRUB_THEME="/usr/share/grub/themes/manjaro-smfont/theme.txt"

# Uncomment to get a beep at GRUB start
#GRUB_INIT_TUNE="480 440 1"

# Uncomment to ensure that the root filesystem is mounted read-only so that
# systemd-fsck can run the check automatically. We use 'fsck' by default, which
# needs 'rw' as boot parameter, to avoid delay in boot-time. 'fsck' needs to be
# removed from 'mkinitcpio.conf' to make 'systemd-fsck' work.
# See also Arch-Wiki: https://wiki.archlinux.org/index.php/Fsck#Boot_time_checking
#GRUB_ROOT_FS_RO=true

Generating grub configuration file … and the lines after GRUB_DISABLE_OS_PROBER=false don’t like like they belong in a grub config file.

pax-eterna · 15 November 2022 22:13

Yeah they did seem a bit incongruous but it was all a default Manjaro Install…this is the first time I’ve even looked at the grub, let alone edited it!!

Nachlese · 15 November 2022 23:07

Perhaps this is solved now?

If not:

this would be o.k.
… with nothing else on the same line - just this:
GRUB_CMDLINE_LINUX="cpufreq.default_governor=performance threadirqs"

In fact:
all these parameters should go to:
GRUB_CMDLINE_LINUX_DEFAULT=

so that the final result looks like this:

GRUB_CMDLINE_LINUX_DEFAULT=“quiet apparmor=1 security=apparmor udev.log_priority=3 cpufreq.default_governor=performance threadirqs”
GRUB_CMDLINE_LINUX=""

(with GRUB_CMDLINE_LINUX= being still empty
but all the parameters being in:
GRUB_CMDLINE_LINUX_DEFAULT=

pax-eterna · 15 November 2022 23:10

Thank you, I will give that a try…

EDIT: Nope that doesn’t work either…Unless it is not the ESC key to press?? If it is, then none of the solutions offered enable me to choose the Kernel.

maycne.sonahoz · 16 November 2022 07:19

Don’t forget to sudo update-grub after modifying /etc/default/grub.

darkcity · 16 November 2022 12:57

what is the complete contents of your /etc/default/grub now?

pax-eterna · 16 November 2022 15:59

Haha, NOW it says a command at line 8 is not found!!

full GRUB is :
GRUB_DEFAULT=saved
GRUB_TIMEOUT=5
GRUB_TIMEOUT_STYLE=menu
GRUB_DISTRIBUTOR=“Manjaro”
GRUB_CMDLINE_LINUX_DEFAULT=“quiet apparmor=1 security=apparmor udev.log_priority=3”
GRUB_CMDLINE_LINUX=“”
GRUB_DISABLE_OS_PROBER=false
Found theme: /usr/share/grub/themes/manjaro/theme.txt
Found linux image: /boot/vmlinuz-5.19-rt-x86_64
Found initrd image: /boot/intel-ucode.img /boot/initramfs-5.19-rt-x86_64.img
Found initrd fallback image: /boot/initramfs-5.19-rt-x86_64-fallback.img
fgrep: warning: fgrep is obsolescent; using grep -F
Warning: os-prober will be executed to detect other bootable partitions.
Its output will be used to detect bootable binaries on them and create new boot entries.
Adding boot menu entry for UEFI Firmware Settings …
Found memtest86+ image: /boot/memtest86+/memtest.bin
/usr/bin/grub-probe: warning: unknown device type nvme0n1.
done

andreas85 · 16 November 2022 16:15

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Your config file for grub seems to be a mess

pax-eterna · 16 November 2022 16:45

One I did not create!! It is exactly as it was from the default Manjaro install…the only editing I have done is from THIS thread!!

And I would suggest “a mess” is exaggerated

Further, it has nothing to do with NOT booting…it has everything to do with Manjaro making it very difficult to swap kernel…what SHOULD be available under the Kernel in Settings Manager, and then reboot, is only available after some arcane grub editing work.

And finally INXI only provides info on the hardware which has NOTHING to do with this issue!

brahma · 16 November 2022 16:53

post your full grub:
cat /etc/default/grub
and use formatting, click this icon in editor: </>

pax-eterna · 16 November 2022 17:04

Jumped back to a post from DarkCity - missed the very bottom comment previously - where it stated (paraphrased) that info under a certain line didn’t look as if it should be there…deleted all that, re-ran update-grub and I now can select kernel at boot.

Thanks

nikgnomic · 18 November 2022 17:48

Most of the PREEMPT_RT patches for pro-audio are included in kernel v6.0 ( v6.1 might be fully patched ) so there is not much additional benefit from using RT kernel

But RT kernel has CONFIG_IRQ_FORCED_THREADING=y by default so threadirqs boot option is not needed

system · 21 November 2022 07:49

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