Score:0

Newly installed 20.04 not showing up in boot list

cn flag

I have a dual-boot laptop with winxp and ubuntu 18.04 32 bit installed. Now I am trying to upgrade my machine to 20.04 64bit version.

Instead of overwriting 18.04, I installed ubuntu 20.04 on a third partition. During installation, when asked to specify boot partition, I selected the old partition where /boot was mounted.

The installation was a breeze. But after restart I still see only the old options in boot list: ubuntu 18.04 and winxp. Even the Advanced options shows the same two 18.04 kernel versions as before. After booting in 18.04, I mounted the partition where 20.04 is installed and I can see all the files there. But I'm not able to boot into it.

Any clues how I can get 20.04 to be visible in GRUB? Was my selection of boot partition wrong?

Score:1
cn flag

open terminal and run:

$ sudo update-grub
makarand avatar
cn flag
This worked. I can now see all the versions in boot list. Thanks for the simple solution.
Score:0
hm flag
Rob

Go back into the live ubuntu (or use the 18.04) and with gparted, you can set the boot flag, set it to the partition of 20.04.

makarand avatar
cn flag
But does that mean I can boot only in to ubuntu 20.04? I don't want to lose access to version 18.04 and win-xp options!
Rob avatar
hm flag
Rob
no, what happend was the 18 grub was probably installed as older 32bit, 20 came with its own newer 64bit but will boot 32 too. they each are installed on their own partitions (unless you have set /boot to somewhere else during install). with the bootflag you tell MBR/GPT where to boot first. if you dont see the other boot options in grub, run a update-grub /dev/sdX (x as where the disc is mostly sda)
Rob avatar
hm flag
Rob
if you have problems try the bios boot manager F12 but you may need to enable that option in the bios first
makarand avatar
cn flag
Thanks. I ran update-grub like @Hossein suggested and update-grub was smart to detect boot info stored on the new partition where 20.04 is installed. It added that entry to GRUB and the next time I booted I could see all versions in the boot list.
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