After installing Debian on a 2nd HD I tried to change some file permissions(as root) on the 1st HD (mounted as /mnt/hda5 - it's a logical partition): chmod 555 /mnt/hda5/some_file
but it keeps saying:
chmod: changing permissions of some_file: Read-only file system
The actual permissions are:
-r-------- 1 root root 21381 2005-01-01 21:18 some_file

Why? I think it has to do with the fact that the file system on hda5 is NTFS (it has on it Win XP). After all, I'm not changing permissions to rwx, only to rx. The same message I get with any code (444, 500, etc.)
I want to do this because I want to be able to read the file as a regular user, not only as root. Is there any way around?

I think, ntfs partitions are mounted read-only in Linux.

I use RH9 and have observed that they are mounted as read-only. I think only FAT-32 can be made rx but not ntfs.

I know that NTFS volumes are by default mounted as read-only (you can enable write access, but at your own risk). I was wondering why I can't change the permissions on a file for another user. After all, why the root can modify access levels on other files stored on an ext3 partition but on a NTFS one not?

Because NTFS knows nothing about Linux'
permissions ... to achieve what you want
one would have to re-write the ntfs driver
to store separate info about perms in some
other file and/or database which would be
a major pain in the neck :)



Cheers,
Tink

Because the partition is mounted read only. Changing permissions on a file requires being able to write to the partition (where do you think file permissions are stored?). Therefore, you can't change permissions on read only file systems. You can remount the permission with a different umask setting, though, which will have the same effect to all file on the permission.

Thanks, got it. Yet it would be nice to be able to listen to my favourite music(stored on NTFS drive) in Linux.

Well, that's not a big deal, and doesn't require
write-access to ntfs ... edit fstab and give the thing
a specific uid/gid in the mount parameters or change
the umask ... e.g.
/dev/hda3 /share ntfs user,rw,uid=1001,umask=000 0 0


Have a play with that...


Cheers,
Tink

Got it! Thanks Tinkster.