Read only root partition

mrajanna · 05-11-2015, 05:25 AM

Dear All,

I have a requirement of changing my root partition to Readonly.

After changing / to readonly in /etc/fstab, I rebooted the system.

Mount points of USB devices is /mnt/sdxx.

But after above changes USB folder is not creating under /mnt/sdXX because of Read only Root partition.

Can I get any work around for this requirement please..

syg00 · 05-11-2015, 05:28 AM

Obviously a ridiculous requirement.

smallpond · 05-11-2015, 05:32 AM

Live OS are using overlayfs on top of read only root.

mrajanna · 05-11-2015, 05:35 AM

If / partition is changed to 'rw' in /etc/fstab, then sdxx directory gets created under /mnt whenever USB is plugged.

But my / partition should be 'ro' and it is the requirement, any workaround please.

pan64 · 05-11-2015, 05:55 AM

goto #3 http://r.duckduckgo.com/l/?kh=-1&udd...-use-overlayfs

veerain · 05-11-2015, 06:16 AM

It may depend on distro. But if you make a static mount point for usb drive then it should be mountable.

mrajanna · 05-11-2015, 08:03 AM

I am not sure of static mount point, I don't know how to make it work.
My distro is Windriver 6.

In my case, root partition will always be mounted as readonly due to security reasons.

When I plug usb device folder I should get USB folder created in /mnt. I am sure USB mount point is under /mnt. But this is not happening.

ondoho · 05-11-2015, 03:26 PM

an operating system cannot "do things" if it's read only.
mounting a usb drive requires write access to parts of the os at least.
i guess the answer to your question lies in post #3.
or, if you explain what you are really trying to achieve, maybe there are other ways to achieve it.

fatmac · 05-12-2015, 09:48 AM

There are certain folders that need to be writable, /etc, /var, /tmp, & /home, (I may have missed another one but from memory, those).
If you want to set your / partition to be read only, these mount points need to be in a separate writable partition.