Ubuntu Cannot change permissions on files I own and have RW to

Question

I have a harddrive full of backups which for me is mounted at /media/chronus_ I have been trying to give another user rw permission to this drive.

The problem is that I cannot change any permissions on this drive, even if i make a new file it puts sets everything to -rw------- here is an excerpt of what i have tried:

madmaze@the-gibson:~$ touch testfile
madmaze@the-gibson:~$ ls -l testfile 
-rw-r--r-- 1 madmaze madmaze 0 2011-01-16 20:11 testfile
madmaze@the-gibson:~$ chmod 777 testfile 
madmaze@the-gibson:~$ ls -l testfile 
-rwxrwxrwx 1 madmaze madmaze 0 2011-01-16 20:11 testfile
madmaze@the-gibson:~$ cd /media/chronos_/Pix/
madmaze@the-gibson:/media/chronos_/Pix$ ls -l
total 4100
-rw------- 1 madmaze madmaze   28226 2011-01-16 20:18 avp.jpg
-rw------- 1 madmaze madmaze    5764 2011-01-16 20:18 avpsmall.jpg
-rw------- 1 madmaze madmaze   98414 2011-01-16 20:18 john.jpg
-rw------- 1 madmaze madmaze   98785 2011-01-16 20:18 lisa.jpg
-rw------- 1 madmaze madmaze 3954281 2011-01-16 20:18 peter.jpg
madmaze@the-gibson:/media/chronos_/Pix$ chmod 777 *.jpg
madmaze@the-gibson:/media/chronos_/Pix$ ls -l
total 4100
-rw------- 1 madmaze madmaze   28226 2011-01-16 20:18 avp.jpg
-rw------- 1 madmaze madmaze    5764 2011-01-16 20:18 avpsmall.jpg
-rw------- 1 madmaze madmaze   98414 2011-01-16 20:18 john.jpg
-rw------- 1 madmaze madmaze   98785 2011-01-16 20:18 lisa.jpg
-rw------- 1 madmaze madmaze 3954281 2011-01-16 20:18 peter.jpg
madmaze@the-gibson:/media/chronos_/Pix$ sudo chmod 777 *.jpg
madmaze@the-gibson:/media/chronos_/Pix$ ls -l
total 4100
-rw------- 1 madmaze madmaze   28226 2011-01-16 20:18 avp.jpg
-rw------- 1 madmaze madmaze    5764 2011-01-16 20:18 avpsmall.jpg
-rw------- 1 madmaze madmaze   98414 2011-01-16 20:18 john.jpg
-rw------- 1 madmaze madmaze   98785 2011-01-16 20:18 lisa.jpg
-rw------- 1 madmaze madmaze 3954281 2011-01-16 20:18 peter.jpg
madmaze@the-gibson:/media/chronos_/Pix$ touch testfile
madmaze@the-gibson:/media/chronos_/Pix$ ls -l testfile 
-rw------- 1 madmaze madmaze 0 2011-01-16 20:25 testfile
madmaze@the-gibson:/media/chronos_/Pix$ chmod 777 testfile
madmaze@the-gibson:/media/chronos_/Pix$ ls -l testfile 
-rw------- 1 madmaze madmaze 0 2011-01-16 20:25 testfile
madmaze@the-gibson:/media/chronos_/Pix$ 

Any Ideas what I could be doing wrongly? The Filesystem is NTFS

Is it possible that NTFS doesnt support other permissions?

Answer 1

Is it possible that NTFS doesnt support other permissions?

Yes. The NTFS driver included in Ubuntu (NTFS 3G) doesn't support ownership and rights changes. From Ubuntu documentation:

The present limitations of this driver are:

• writing files encrypted or compressed at the filesystem level (does not include .zip, .gz, .rar files since they are compressed on the file, not the file system level)
• changing NTFS file ownership and access rights

Answer 2

You can change the permissions of your mount files with something like

mount -t ntfs -o umask=022,uid=madmaze,gid=madmaze /dev/sdb1 /media/chronus

where umask=022 gives 644 (-rw-r--r--) for file permissions, and 755 (drwxr-xr-x) for directory permissions.