Permission problems at mounting ext4 filesystem on fstab

Question

I have installed 2 linux distributions, Fedora 15 and Ubuntu 11.04. I have a partition formated in ext4 filesystem and i mounted using the /etc/fstab file on /mnt/files/ mountpoint. It mounts correctly in both distros but i have one problem with permissions. This exapmple illustrates it:

If i create a folder /mnt/files/test/ using mkdir in this common partition from Ubuntu, when im on Fedora and try to create a directory inside this folder, say /mnt/files/test/test2 it says that i dont have the permissions. I have read som solutions, and the most of them says that i have to change the permissions or the owning of the folders using recursively chmod or chown but the problem is that i have to do this every time that i create a new file or folder on the other distro.

I want to know if is there any option on the fstab file that help me to achieve this. I have tried the uid, gid and umask options but it looks like this options cant be used on a ext filesystem.

The entry en my /etc/fstab file is:

UUID=<uuid> /mnt/files ext4 defaults 0 0

I hope you can help me.

Regards.

Answer 1

Your /etc/fstab really doesn't have anything to do with this.

You major problem is most likely that the UID/GID associated with your account on the two installations are different.

You can either

• Setup groups using identical GIDs on both installations, and setup your permissions to be based on a common group
• Adjust the UID/GID of one of the accounts so they are identical between your two installs.

To confirm that the two are different look at your account and primary group in the /etc/passwd, and /etc/group files of the two systems.