Why is my file system mounted as read-only?

Question

I've put together a small system with busybox, a Linux kernel, and a small file system, putting stuff in as it seemed necessary -- I don't know if I've been learning much from this, but I started out pretty clueless, so it sure hasn't been a smooth ride. So I suspect I might be missing some stuff in my filesystem, but I'm really not sure what I might need to add next.

I can boot into my system by typing in the following grub commands: $set root=(hd0,msdos1) \ linux /vmlinuz root=/dev/sda1 \ boot$

Once the boot messages stop, I'm left with this (I'm not sure if it's related but there's a line there that says: VFS: Mounted root (ext3 filesystem) readonly on device 8:1):

I can't modify the filesystem: ln: bin/mkdir Read-only file

It's funny because I can manually mount /proc just fine: mounting /proc

Why is my file system read-only? What would I need to set up to get it to work?

It's not unusual for a system to boot `/` readonly at first and then remount it rw later on. (I think the idea is that one would like to get to binaries like the file system check e2fsck in `/sbin/` without risking breaking anything.) — Ulrich Schwarz, Feb 27 '12 at 11:33
maybe your filesystem is corrupt, have you tried to check it ? — Coren, Feb 27 '12 at 13:16

score 24 · Answer 1 · answered Dec 18 '17 at 22:53

24

I had a similar issue that is not solved with the solution above. Linux may mount a drive as 'read-only' because of Fastboot on Windows 10. A shutdown with the Fastboot feature keeps the Windows kernel and session running albeit it closes all applications and logs off users. By turning off Fastboot, windows will do a cold shutdown and linux will be able to mount the drive safely. You will loose the fast windows boot as a consequence.

To turn-off fast-boot on windows 10 do the following:

Go to Control Panel.
Click Power Options.
Choose "what the power buttons do."
Click "Change settings that are currently unavailable."
Find and uncheck "Turn on fast startup."
Save changes.
Shutdown and boot linux.

References: https://itsfoss.com/solve-ntfs-mount-problem-ubuntu-windows-8-dual-boot/ https://www.howtogeek.com/243901/the-pros-and-cons-of-windows-10s-fast-startup-mode/

answered Dec 18 '17 at 22:53

Diaz

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I doubt, this is a reasonable answer for a question from 2012. But as a reader from the future, I very much appreciate the pointer into the right direction. – m8mble Apr 09 '20 at 20:37
it worked like charm. – Deepam Gupta Oct 16 '20 at 13:44
Thanks a lot, working indeed like a charm – Alf Nov 12 '20 at 08:24
Thanks a lot. This solution worked for me. – Arjun Panicker Jun 11 '21 at 04:44
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Thanks, you saved my time. – adeel iqbal Mar 15 '22 at 04:55
The problem I had was that -also on a dual-boot Ubuntu/Windows- Windows didn't cleanly unmount its drives (hard reset). Just booting into Windows, cleanly shutting down and restarting in Ubuntu solved the issue. – Jakke Apr 19 '22 at 10:25

score 21 · Accepted Answer · edited Jan 15 '21 at 09:55

21

Try to search in dmesg | less.

If you would like remount it to read-write, use mount -o remount,rw /

edited Jan 15 '21 at 09:55

Amin Soheyli

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answered Feb 27 '12 at 09:52

Jan Marek

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I run that command but got `mount: cannot remount /dev/mmcblk0p2 read-write, is write-protected`. – SAMPro May 25 '17 at 03:26
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mmcblk0p2 sounds like an SD card. These (or micro-SD to SD adapters) often have a small physical switch on the side that sets them read-only. – jazzpi May 13 '20 at 15:46
@SAMPro how did you fix this? (same question for any reader who fixed it; please help the community! I'm getting the same message – Nathan majicvr.com Aug 16 '20 at 21:22
Any found the solution for write-protected – Rohit Nishad May 26 '21 at 18:15

score 2 · Answer 3 · edited Dec 29 '19 at 03:01

2

@Diaz Great advice, solved my issue. However, the "Turn on fast startup" didn't turn up in my Windows 10 installation. So I disabled the feature directly in the registry:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SessionManager\Power\HiberbootEnabled=0

Booted Debian and voila - SDD rw again.

edited Dec 29 '19 at 03:01

answered Dec 28 '19 at 23:52

jamacoe

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Why is my file system mounted as read-only?

3 Answers3

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