Arch Linux

Fred Barclay

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From: /home

Registered: 2015-02-27

Posts: 123

<SOLVED>"Root device not mounted read-write" warning

Every time I boot Arch up, I get the following warning:
"The root device is not configured to be mounted read-write! It may be fsck'd again later."

So far I have done absolutely nothing to the partition, other than set a root password and hostname.
Everything I've read online indicates that this is a problem with the bootloader configuration files mounting the partition as ro instead of rw. Unfortunately, I don't have a bootloader installed. Arch is installed on sda2, and LMDE is installed on sda1, and I just use LMDE's GRUB to boot Arch.

Any idea how to fix this?

Last edited by Fred Barclay (2015-02-28 22:40:31)

bteeuwen170

Member

From: Belgie

Registered: 2015-02-27

Posts: 2

Re: <SOLVED>"Root device not mounted read-write" warning

There's already multiple threads on the same topic. This one for example: https://bbs.archlinux.org/viewtopic.php?id=167552.

Head_on_a_Stick

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From: London

Registered: 2014-02-20

Posts: 7,732

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Re: <SOLVED>"Root device not mounted read-write" warning

You could make a custom GRUB entry for Arch and add "rw" to the kernel line.

In LMDE, add the Arch entry to /etc/grub.d/40_custom -- just copy&paste the entry from /boot/grub/grub.cfg and add the "rw" option.

You will need to generate the grub.cfg afterwards:

# update-grub

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Fred Barclay

Member

From: /home

Registered: 2015-02-27

Posts: 123

Re: <SOLVED>"Root device not mounted read-write" warning

This is what is under /boot/grub/grub.cfg for Arch:

### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Arch (on /dev/sda2)" --class gnu-linux --class gnu --class os {
    insmod part_msdos
    insmod ext2
    set root='(hd0,msdos2)'
    search --no-floppy --fs-uuid --set=root ********************************
    linux /boot/vmlinuz-linux root=/dev/sda2
    initrd /boot/initramfs-linux.img
}

Where would I add the rw option?
Thanks!

NOTE: --set=root did have numbers instead of asterisks, but I didn't want to post them.

Head_on_a_Stick

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From: London

Registered: 2014-02-20

Posts: 7,732

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Re: <SOLVED>"Root device not mounted read-write" warning

Where would I add the rw option?

On the line that starts with "linux" just after "root=/dev/sda2"

Be aware that this file will be overwritten every time the LMDE kernel (or initramfs) is upgraded -- this is why I advise the use of /etc/grub.d/40_custom instead.

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Fred Barclay

Member

From: /home

Registered: 2015-02-27

Posts: 123

Re: <SOLVED>"Root device not mounted read-write" warning

so /etc/grub/d/40_custom would look like

menuentry "Arch (on /dev/sda2)" --class gnu-linux --class gnu --class os {
    insmod part_msdos
    insmod ext2
    set root='(hd0,msdos2)'
    search --no-floppy --fs-uuid --set=root ********************************
    linux /boot/vmlinuz-linux root=/dev/sda2 rw
    initrd /boot/initramfs-linux.img
}

and the rw is without quotes?

Thanks

nullified

Member

From: Massachusetts, USA

Registered: 2013-12-09

Posts: 468

Re: <SOLVED>"Root device not mounted read-write" warning

Fyi, chunks of code are easier on the eyes for most when code tags are used. likeso:

menuentry "Arch (on /dev/sda2)" --class gnu-linux --class gnu --class os {
    insmod part_msdos
    insmod ext2
    set root='(hd0,msdos2)'
    search --no-floppy --fs-uuid --set=root ********************************
    linux /boot/vmlinuz-linux root=/dev/sda2 rw
    initrd /boot/initramfs-linux.img
}

---

"We may say most aptly, that the Analytical Engine weaves algebraical patterns just as the Jacquard-loom weaves flowers and leaves." - Ada Lovelace

Head_on_a_Stick

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From: London

Registered: 2014-02-20

Posts: 7,732

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Re: <SOLVED>"Root device not mounted read-write" warning

Yes and yes.

Add that entry underneath the extant content of /etc/grub.d/40_custom:

#!/bin/sh
exec tail -n +3 $0
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.

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Fred Barclay

Member

From: /home

Registered: 2015-02-27

Posts: 123

Re: <SOLVED>"Root device not mounted read-write" warning

Fyi, chunks of code are easier on the eyes for most when code tags are used. likeso:

menuentry "Arch (on /dev/sda2)" --class gnu-linux --class gnu --class os {
    insmod part_msdos
    insmod ext2
    set root='(hd0,msdos2)'
    search --no-floppy --fs-uuid --set=root ********************************
    linux /boot/vmlinuz-linux root=/dev/sda2 rw
    initrd /boot/initramfs-linux.img
}

How to use code tags?

Last edited by Fred Barclay (2015-02-28 20:16:08)

Head_on_a_Stick

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From: London

Registered: 2014-02-20

Posts: 7,732

Website

Re: <SOLVED>"Root device not mounted read-write" warning

How to use code tags?

[᠎code]post terminal output here[᠎/code]
https://bbs.archlinux.org/help.php#bbcode

EDIT: Was that not obvious from the quoted text?

Last edited by Head_on_a_Stick (2015-02-28 20:17:44)

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Fred Barclay

Member

From: /home

Registered: 2015-02-27

Posts: 123

Re: <SOLVED>"Root device not mounted read-write" warning

How to use code tags?

[᠎code]post terminal output here[᠎/code]
https://bbs.archlinux.org/help.php#bbcode

EDIT: Was that not obvious from the quoted text?

I'd tried it earlier that way--must have done something wrong--and so I figured that there was something I was missing.
Here goes:

apt moo

Have you moo'ed today?

Fred Barclay

Member

From: /home

Registered: 2015-02-27

Posts: 123

Re: <SOLVED>"Root device not mounted read-write" warning

Didn't work

Quick review: I added

menuentry "Arch (on /dev/sda2)" --class gnu-linux --class gnu --class os {
    insmod part_msdos
    insmod ext2
    set root='(hd0,msdos2)'
    search --no-floppy --fs-uuid --set=root ********************************
    linux /boot/vmlinuz-linux root=/dev/sda2 rw
    initrd /boot/initramfs-linux.img
}

to /etc/grub.d/40_custom and then ran

sudo update-grub

inside LMDE.
The only noticeable difference is that I now have 2 Arch entries in the GRUB menu.

Head_on_a_Stick

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From: London

Registered: 2014-02-20

Posts: 7,732

Website

Re: <SOLVED>"Root device not mounted read-write" warning

In which case I would advise installing GRUB from Arch and letting that control the booting process instead.

# pacman -Syu grub os-prober
# grub-install --target=i386-pc --recheck /dev/sda
# grub-mkconfig -o /boot/grub/grub.cfg

https://wiki.archlinux.org/index.php/Be … therboards

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Fred Barclay

Member

From: /home

Registered: 2015-02-27

Posts: 123

Re: <SOLVED>"Root device not mounted read-write" warning

That worked. Thanks!
Of course, I've got another problem now...