understanding /etc/fstab

guldo · 05-16-2004, 04:56 PM

Hello.
Though I searched the forum, I couldn't find answers to this question; maybe it's just too easy...
I think I'm too stupid to understand how mount options work.
I looked at the man pages of mount and fstab, but I cannot understand.
I'd just like to have read/write access, as normal user, to a certain partition.
I tried many combos of rw, default, user, exec, noauto, and the like, with no success.
The user can mount the partition, but cannot write in it, due to permissions.
The partition fs is ext3.

What's the right syntax?

Thank you,

Guldo

mbegovic · 05-16-2004, 05:15 PM

You change permissions (or modes) with chmod. This:

Code:

chmod 777 files

Gives full permissions to everybody. The three numbers refer to file owner, group, and everybody else. 7 means read-write-execute, 6 means read-write, 5 read-execute, 4 read, 2 write, 1 execute (notice that you simply add the numbers to combine the different permissions).

guldo · 05-16-2004, 05:21 PM

Thank you for your reply.
I know I could change permissions using chmod, but I would like to mount the partition in order to let the mounter (user) read/write in it.
I'd have to edit /etc/fstab so that any user could simply do:
mount /this-partition
and have read/write access.
How is this achieved?

Thanks,

Guldo

Kristijan · 05-16-2004, 08:46 PM

What you could try is mounting the partition with the umask option.

Try something like this

Code:

mount -o umask=000 /dev/device /mnt/mount_point

A umask of 000 will give the persmissions rwxrwxrwx to that partition. I usually use an option of 022. Which is rwxr-xr-x. Umask sort of works backwards, 000 = 777, 022 = 755 etc... Play around till you find one which works for you.

Take note that if the parition you are mounting is NTFS, although it can be done, writing to a NTFS parition is somewhat dodgy. Best google around before you start writing to it.

Good Luck

Kristijan

guldo · 05-16-2004, 09:18 PM

Quote:

Originally posted by Kristijan
What you could try is mounting the partition with the umask option.

I thought the umask option was related to vfat fs; in fact:

Code:

# mount -o umask=000 -t ext3 /dev/hde7 /backup/
mount: wrong fs type, bad option, bad superblock on /dev/hde7,
       or too many mounted file systems

guldo · 05-17-2004, 04:49 PM

Could you help me, please?
I have to figure this out...

guldo · 05-23-2004, 02:58 PM

moby · 05-23-2004, 04:28 PM

I could be wrong, but at the mount point directory you can also chmod the permission of the access.

guldo · 05-23-2004, 04:43 PM

Quote:

Originally posted by moby
I could be wrong, but at the mount point directory you can also chmod the permission of the access.

And I did.
I created the mountpoint as an ordinary directory, owned by the no-root user.
As this no-root user mounts it, its owner becomes root, and the user cannot write into it.

Why?

Thanks,

Guldo