Arch Linux

t4sk1n

Member

From: Bangladesh

Registered: 2020-04-26

Posts: 5

[SOLVED] /proc and /sys have become read-only

So I have root directory which uses ext4 filesystem and have a separate partition to be mounted as /boot.

Today all on a sudden, my system rebooted itself and every time I try to reboot it shows "failure to load kernel modules".

So I insert an Arch live ISO and arch-chroot into the root directory after mounting it as mounting it at appropriate points. From what I've observed:

1. ls -l / outputs that /sys and /proc themselves do not have any write permissions; I tried reinstalling linux and linux-firmware where it showed an error saying opening '/sys/devices/system/cpu/microcode/reload' failed and it is a 'Read-only filesystem' but that file has write permissions for the user (root)

2. While these directories are shown as completely read-only, some (I think all) of its subdirectories seem to have write permissions for the user (but not all the files, it seems)

Last edited by t4sk1n (2020-10-18 19:19:53)

t4sk1n

Member

From: Bangladesh

Registered: 2020-04-26

Posts: 5

Re: [SOLVED] /proc and /sys have become read-only

also, I've tried using 'chmod +w --recursive /sys' but it only echoes "read-only file system" for each file and does not make any change

koffeinfriedhof

Member

Registered: 2017-11-30

Posts: 89

Re: [SOLVED] /proc and /sys have become read-only

Hello!

/sys and /proc are created on every boot and should not be changed!

Normally read-only mode is a failsafe mode if there are problems on your harddisk or filesystem. Could you start from your live ISO and `fsck` your root device? If you need further help, have a look at `journalctl -b -xep 0..4` which will show all warnings and errors since last reboot. We perhaps need to know your harddisk partitions and mounting, so provide

cat /etc/fstab
mount

# as root
blkid

and any error that might be related.

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,619

Re: [SOLVED] /proc and /sys have become read-only

/sys and /proc are virtual file systems populated by the kernel that do not exist on your disk, it's hard to impossible for these to be related to what your actual issue is.

The more likely reason for your broken boot is that your kernel image was not properly written during the update, if you've actually properly reinstalled the kernel, are you just hanging yourself up on that message and haven't tried to reboot yet?

FWIW from the chroot, what's your output for

pacman -Q linux
file /boot/vmlinuz-linux

https://wiki.archlinux.org/index.php/Li … in_clients

t4sk1n

Member

From: Bangladesh

Registered: 2020-04-26

Posts: 5

Re: [SOLVED] /proc and /sys have become read-only

Hello!

/sys and /proc are created on every boot and should not be changed!

Normally read-only mode is a failsafe mode if there are problems on your harddisk or filesystem. Could you start from your live ISO and `fsck` your root device? If you need further help, have a look at `journalctl -b -xep 0..4` which will show all warnings and errors since last reboot. We perhaps need to know your harddisk partitions and mounting, so provide

cat /etc/fstab
mount

# as root
blkid

and any error that might be related.

Thanks for the response. My /etc/fstab entries somehow got removed which was the actual problem. Booting using fallback ramdisk succeeded and I then rebooted to the live ISO and used  genfstab to populate that file once again and now the problem is solved.

/sys and /proc are virtual file systems populated by the kernel that do not exist on your disk, it's hard to impossible for these to be related to what your actual issue is.

The more likely reason for your broken boot is that your kernel image was not properly written during the update, if you've actually properly reinstalled the kernel, are you just hanging yourself up on that message and haven't tried to reboot yet?

FWIW from the chroot, what's your output for

pacman -Q linux
file /boot/vmlinuz-linux

https://wiki.archlinux.org/index.php/Li … in_clients

Thanks for the response. The commands you provided showed expected values. My issue is now solved (see above).

Last edited by t4sk1n (2020-10-19 08:44:25)