Using chown, chgrp, chmod on a vfat partition?
 

Hi.

In my Linux-Windows dual boot system MS Windows is under the /mnt/windows directory.
It is a vfat partition, and vfat file systems lack of support for
unix-style permissions, so I don't manage to normally use the `chmod',
`chown' and `chgrp' commands within that directory.
Does anybody know if there is a way
to make those commands work also in a vfat partition?

What I want is to store mail in /mnt/windows. To do so, my mail agent
is using chmod as a security precaution
(to ensure that my messages are not readable by anyone other
than myself), and so it has problems with the vfat file system /mnt/windows.
I worked the problem out by specifing uid=501 and gid=501 in /etc/fstab;
but then no other user than 501 (me) will be able to put his/her mail
into /mnt/windows.

I hope I was clear enough.
Any suggestion?

Rodolfo

You can use 'umask' in /etc/fstab to specify default permissions for the partition. such as 777 or whatever, so that everyone can use it. Yes, you can use specific guid etc, but you can't really do much with individual folders on the FAT partition. if you see what i mean - it's the whole partition or nothing.

unless someone would correct me ;-)

Thanks.

I see: the whole partition or nothing.
Then the question becomes:
would it be possible to change my MS Windows vfat partition
into another kind of partition, e.g. the same kind of
the other linux partitions I have on my hard disk
(Journalised FS ext3, if I remember well?), that does not
have such problems?

Rodolfo

no, unfortunatley not. MS Windows will only run on FAT or NTFS partitions.


I think the best way to tackle this is to see how/why your mail agent is checking file permissions. It won't actually be using 'chmod' as this changes ownerships. Is it checking for ownership of directories that is saves mail into or something?


Can this be disabled?

My mail agent (gnus) is checking file permissions in order to prevent other users
to read my mail: it takes off read and write permissions to users different from
`me' onto the files it creates, I'm not sure about directories.
So, this can't be disabled, or anyway it wouldn't be right for its `philosophy',
and also for practical reasons.

The ownership change could maybe work the problem out though,
because if I could change the ownership of a certain directory
then I could maybe play with chown, chgrp and chmod until I worked it out.
Instead, the chown command does not work for /mnt/windows.

But maybe an NTFS partition would work better?
I know there are writing problems with it, but maybe they can be
solved?

Rodolfo

NTFS doesn't work well with linux i'm afraid. And FAT is inherintly unsecure. So, i'm not sure what your options are here. maybe create separate partitions for your mailboxes. Although this a hudge kludge of course........

Well, thanks indeed for your help!

Rodolfo

Maybe a partial solution:
the user who's fecthing mail could first set the ownership of /mnt/windows
with the `mount' command with its options `uid' and `gid'.
Could anyone suggest the right syntax for that?
I didn't manage to find it out from the mount manual.

Rodolfo