Cfrgtkky

I tried to update my grub config file to timeout to 0 value, so OS starts quickly. I modified /etc/default/grub configuration file on my Ubuntu 18.04 and then ran:

sudo update-grub

and it didn't work. I also ran:

sudo grub-mkconfig

sudo update-grub

but they didn't work.

I searched a lot on the web to solve this issue, but all guides say to run the update-grub command to update grub by /etc/default/grub config file.
I don't know if is Ubuntu 18.04 that handles grub files in a different way, but I cannot update my grub with my parameters.

This is my /etc/default/grub file:

# If you change this file, run 'update-grub' afterwards to update

# /boot/grub/grub.cfg.

# For full documentation of the options in this file, see:

# info -f grub -n 'Simple configuration'



GRUB_DEFAULT=0

#GRUB_HIDDEN_TIMEOUT=0

GRUB_HIDDEN_TIMEOUT_QUIET=true

GRUB_TIMEOUT=0

GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

GRUB_CMDLINE_LINUX=""



# Uncomment to enable BadRAM filtering, modify to suit your needs

# This works with Linux (no patch required) and with any kernel that obtains

# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)

#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"



# Uncomment to disable graphical terminal (grub-pc only)

#GRUB_TERMINAL=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 `vbeinfo'

#GRUB_GFXMODE=640x480



# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux

#GRUB_DISABLE_LINUX_UUID=true



# Uncomment to disable generation of recovery mode menu entries

#GRUB_DISABLE_RECOVERY="true"



# Uncomment to get a beep at grub start

#GRUB_INIT_TUNE="480 440 1"

In /boot/grub/grub.cfg file there is a condition, almost at the end of the file, that sets the timeout to 10 if the timeout is set to 0. In other words, if you set the timeout to 0 in your /etc/default/grub and then update grub, the condition above reset it to 10 seconds.

if [ "${timeout}" = 0 ]; then

     set timeout=10

fi

However, /boot/grub/grub.cfg is a read-only file and I cannot remove that condition. I made some tests with different values of the timeout in /etc/default/grub. I tried with 1ms (0.001), 0.1s and 1s and I found out that values below 1 (like 0.1 and 0.001) work in the same way and almost like timeout set to 0.

Uncomment GRUB_HIDDEN_TIMEOUT=0 and run update-grub again.

Like the other answers say, uncomment GRUB_HIDDEN_TIMEOUT and run update-grub. Then comment out the

if [ "${timeout}" = 0 ]; then

  set timeout=10

fi

section in /boot/grub/grub.cfg. In vim you can just override the read-only property with an exclamation point :x!. Or you can run

sudo chmod +w /boot/grub/grub.cfg

sudo vim /boot/grub/grub.cfg

sudo chmod -w /boot/grub/grub.cfg

to temporarily have write permission while editing the file.

In my case, the problem was that my system didn't support "recordfail" which caused a separate block to get added to the grub.cfg which defaults to a timeout of 30 seconds. The relevant code in /etc/grub.d/00_header:

if [ "$recordfail_broken" = 1 ]; then

  cat << EOF

if lsefi; then

  set timeout=${GRUB_RECORDFAIL_TIMEOUT:-30}

  if [ x$feature_timeout_style = xy ] ; then

    set timeout_style=menu

  fi

fi

EOF

The fix is simply to add a value for GRUB_RECORDFAIL_TIMEOUT in /etc/default/grub and run update-grub again. For example:

GRUB_CMDLINE_LINUX_DEFAULT=""

GRUB_CMDLINE_LINUX=""



# Adjusted timeout for system which doesn't support recordfail

GRUB_RECORDFAIL_TIMEOUT=2



# Uncomment to enable BadRAM filtering, modify to suit your needs

# This works with Linux (no patch required) and with any kernel that obtains

# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)

#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"

You can set GRUB_TIMEOUT to 0.

The part overwriting timeout value is written in ajust_timeout function in the top of /etc/grub.d/30_os-prober.

ajust_timeout () {

...

if [ "${timeout}" = 0]; then

  set timeout=10

fi

...

}

So, you can set the value by editing the file and comment out if-block.