Issues with grub menu

[jsnotlout1]

So, I thought it was a grand idea to dual boot two Ubuntu installs on my Chromebook, I set the root, home, and swap partition to my USB stick instead of eMMC. The install worked, but it was too slow, the USB could not handle it. So I was going to swap to using my micro SD which has a much better read speed, but now if I dont have the USB with the second Ubuntu installation in the port when i boot up, grub freaks out. I installed the bootloader on the eMMC with the checkbox in the bottom left and it did not overwrite my previous Ubuntu as i feared it would. I don't know how to undo this mess I have created

[Ralphred]

So, it sounds like grub is looking for the boot or efi directory on the USB stick.

If you need it to boot, insert it and let it boot (but boot the the "eMMC version" of the OS if you can).

You can then use grub-install with the --boot-directory= or the --efi-directory= switch so that they point to the eMMC and not the USB stick.

 

These two sections of the gentoo handbook cover manual grub installation, but if you get stuck tell us whether you are BIOS or UEFI booting and then instructions can be more tailored to your set-up.

[Haswellx86]

Your post is too complicated. So if I understand correctly, you installed 2 Ubuntu installs, set both their root, home and swap on your USB stick, then switched the root, home and swap of the first Ubuntu install to your SD card, leaving the root, home and the swap of the second Ubuntu install on your USB stick?

 

And exactly do you mean by "GRUB freaks out"? What does it show?

 

As @Ralphred might work, but if OP only set the root, home and swap on the USB stick, then GRUB should be able to access the kernel to boot. But what I don't know is what happens when a UNIX system tries to boot a system without any user accounts configured. My guess is that it will enter single user mode in the root account at the root (/) directory.

[Ralphred]

Grub2 only cares about the efi/boot directory being accessible and containing the files the menu says it will, anything beyond that being missing is a kernel panic or degraded system.

13 minutes ago, Gat Pelsinger said:

what happens when a UNIX system tries to boot a system without any user accounts configured

It boots.

[Haswellx86]

2 minutes ago, Ralphred said:

It boots.

So you mean like if I using the plain TTY login, it will still just show the login prompt but we can't login? And what if are using a display manager like OP on Ubuntu? What default user account would it show?

[Ralphred]

1 hour ago, Gat Pelsinger said:

What default user account would it show?

Depends, the convention is all accounts under UID 1000 are system accounts and aren't displayed, but UID 0 always exists, so you can log in with that. Considering the the *buntus are sudo based for priv escalation UID 1000 will exist too, as part of the default install.

[jsnotlout1]

3 hours ago, Gat Pelsinger said:

Your post is too complicated. So if I understand correctly, you installed 2 Ubuntu installs, set both their root, home and swap on your USB stick, then switched the root, home and swap of the first Ubuntu install to your SD card, leaving the root, home and the swap of the second Ubuntu install on your USB stick?

 

And exactly do you mean by "GRUB freaks out"? What does it show?

 

As @Ralphred might work, but if OP only set the root, home and swap on the USB stick, then GRUB should be able to access the kernel to boot. But what I don't know is what happens when a UNIX system tries to boot a system without any user accounts configured. My guess is that it will enter single user mode in the root account at the root (/) directory.

I installed every partition but he boot loader on the other USB

 

it shows the grub shell.

[jsnotlout1]

3 hours ago, Ralphred said:

So, it sounds like grub is looking for the boot or efi directory on the USB stick.

If you need it to boot, insert it and let it boot (but boot the the "eMMC version" of the OS if you can).

You can then use grub-install with the --boot-directory= or the --efi-directory= switch so that they point to the eMMC and not the USB stick.

 

These two sections of the gentoo handbook cover manual grub installation, but if you get stuck tell us whether you are BIOS or UEFI booting and then instructions can be more tailored to your set-up.

THANK YOU! just grub-install worked to reset. Its back to booting without the USB. And now I know more about linux Is there any better ways to add a dual boot Ubuntu? Should I put the bootloader somewhere else other than the built in eMMC

[Ralphred]

28 minutes ago, jsnotlout1 said:

Should I put the bootloader somewhere else other than the built in eMMC

So, you should have your bootloader on the "most non-removable drive", so in this case I'd guess that's your eMMC. Even if you were to install another OS, you should go back to your "default install" and let that grub add the new OS to your bootloader (it has modules for this, OS-prober etc.).

It's also worth reading about grub-mkrescue, so you can have a "removable copy of your bootloader" just in case something happens to yours, then you can use it as a rescue device. I have a very old 256meg USB stick I use for this sort of thing, so old it has one of those read-only switches so I can "lock it" for safety.

 

EDIT: If you are only installing another OS for testing, it's OK to let it install is own boot loader on it own drive using it's own efi directory, then you can just use the BIOS menu to boot from that drive without affecting your "normal install" at all.

[g0ated]

7 hours ago, Gat Pelsinger said:

So you mean like if I using the plain TTY login, it will still just show the login prompt but we can't login? And what if are using a display manager like OP on Ubuntu? What default user account would it show?

Afaik most distros will setup root acc by default and what you’re saying is separate from the boot process. And ubuntu forces you to create an acc so your scenario iirc is not possible in the first place. 

[Ralphred]

21 hours ago, goatedpenguin said:

will setup root acc by default

It's not even a case of "setting up", if it doesn't exist there is no user to run the init, kernel, etc.

It might be possible on an embedded system to have the appearance of "no user", but it is still there (without some serious kernel hacking).

 

If anyone uninitiated takes a look at /etc/passwd I think they'll be surprised by the number of system users that exist to create user and group "file security domains".

[g0ated]

10 hours ago, Ralphred said:

It's not even a case of "setting up", if it doesn't exist there is no user to run the init, kernel, etc.

It might be possible on an embedded system to have the appearance of "no user", but it is still there (without some serious kernel hacking).

 

If anyone uninitiated takes a look at /etc/passwd I think they'll be surprised by the number of system users that exist to create user and group "file security domains".

Would guest be considered a user or something temporary? And also many smart TVs like the bravia ones run on android iirc so it is possible and used a lot no? i.e the kernel hacking part is already done no?

[Ralphred]

9 hours ago, goatedpenguin said:

run on android

Android's a good example actually, whilst the end user doesn't really interact with any user accounts as we know them (on a PC running *nix), they are there in the background.

[g0ated]

42 minutes ago, Ralphred said:

Android's a good example actually, whilst the end user doesn't really interact with any user accounts as we know them (on a PC running *nix), they are there in the background.

So essentially there is a user but with no login actually required and all online activities etc. are just saved to your say google acc? 

[BoomerDutch]

7 hours ago, Ralphred said:

Android's a good example actually, whilst the end user doesn't really interact with any user accounts as we know them (on a PC running *nix), they are there in the background.

You could go to developer mode and check ram and services you'll see apps and system apps that you don't usually see, the most of them anyway.

 

6 hours ago, goatedpenguin said:

So essentially there is a user but with no login actually required and all online activities etc. are just saved to your say google acc? 

I think that's different to all brands some may be so and some has extra security to it, i hope.

 

If you know your own system that you build it and technically you can chroot into arch for example and change things around. But this method is only locally anyway so it's not most scary thing unless you're important person or for some reason and your hardware gets stolen then yeah you're screwed.

 

There is disk encryption that would solve this issue it usually happens at installing operation system.