Question about boot partition.

thinkanish · 2022-02-09 16:56:15

Hi,

I previously posted on this forum regarding Arch not booting after a long time update here -
https://bbs.archlinux.org/viewtopic.php?id=273648

Now, I was successfully able to boot. The problem was, I have the partition setup like this :

/dev/sda5 - boot
/dev/sda7 - root
/dev/sda8 - var
/dev/sda9 - home

It was complaining that vmlinuz-linux was not found. But when I checked the boot partition (/dev/sda5), vmlinuz-linux was there.
I proceeded to mount all the partitions except the boot partition (/dev/sda5) and checked the /mnt/boot directory. There I found that there is grub, initramfs and no vmlinuz-linux.
Now, I ran "pacman -S linux" without mounting boot partition and then did a reboot.
Now everything works fine. The system boots properly.

Now, my doubt is, what is the role of the boot partition (/dev/sda5)? should I continue with this setup? or should I repair the system?

Thanks

V1del · 2022-02-09 17:04:20

This depends on how GRUB is configured which depends on the mount setup with which you ran grub-install and grub-mkconfig. In this case you will have initially ran the grub-install command without having had the "boot" partition mounted. Which will lead to the default config and kernel lookup happening on the boot directory on your root partition.

So in that case yes, the boot partition serves no purpose. Whether you want to continue like this depends on what you want to do, yes you can definitely continue like this. If you have a need for the distinct partition for some reason, you need to mount it and then explicitly rerun the grub-install command, copy/install the kernel images, and rerun grub-mkconfg.

ewaller · 2022-02-09 17:08:12

I don't think you are booting from the volume from which you think you are booting.
Is this a BIOS or a uEFI system? I bet you are booting straight to your root partition (which hints at BIOS)

mkoan · 2022-02-09 17:09:35

Hi,
If your system works fine, after a reboot. Possibly you didn't unmount /dev/sda5 from the fstab file and after a kernel update, system repaired itself. You do not need to repair, system already repaired.

thinkanish · 2022-02-09 17:11:56

Hello,

Thanks for your replies.
Yes. I have a BIOS system.
okay then. I will continue with this setup.

ewaller · 2022-02-09 18:01:11

Yeah, so I bet the MBR is configured to use the GRUB on your root volume, not the one on the boot volume.
I don't use grub myself, but I wager V1del's advise will get that MBR pointing to the boot partition as one would expect.

Personally, I boot using an EFI stub.

thinkanish · 2022-02-10 02:48:00

V1del wrote:

So in that case yes, the boot partition serves no purpose. Whether you want to continue like this depends on what you want to do, yes you can definitely continue like this. If you have a need for the distinct partition for some reason, you need to mount it and then explicitly rerun the grub-install command, copy/install the kernel images, and rerun grub-mkconfg.

Thanks. May I know why there was a separate boot partition when one can directly boot from the root partition? (I am trying to guess the reason why I have did a separate partition since it was very long time ago).

ewaller · 2022-02-10 03:06:17

uEFI requires a vfat partition.

For BIOS, If you have multiple operating systems, a separate boot partition is used to decouple them. Why make BSD or Windows count on the existence of your Linux partition? What if the Linux volume were to be corrupted? You could no longer boot it, or any other OS that was configured in Grub on the dead partition.

thinkanish · 2022-02-10 08:53:19

okay. I am trying to gather my thoughts after reading your answer.
You say that if I have another OS (Windows or BSD) installed in my system along side arch, it is better to have a separate boot partition because, if when messing up with root partition, if I corrupt it, then I cannot boot into the other OS (windows or BSD) either. correct?

Its actually a BIOS/MBR system (very old ~12 years) dual booting Windows 7 with Archlinux. So, will go ahead and better repair my boot partition.

Thanks.

Arch Linux

#1 2022-02-09 16:56:15

Question about boot partition.

#2 2022-02-09 17:04:20

Re: Question about boot partition.

#3 2022-02-09 17:08:12

Re: Question about boot partition.

#4 2022-02-09 17:09:35

Re: Question about boot partition.

#5 2022-02-09 17:11:56

Re: Question about boot partition.

#6 2022-02-09 18:01:11

Re: Question about boot partition.

#7 2022-02-10 02:48:00

Re: Question about boot partition.

#8 2022-02-10 03:06:17

Re: Question about boot partition.

#9 2022-02-10 08:53:19

Re: Question about boot partition.

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