I have an USB3.0 external hard disk, partitioned to 3 NTFS partitions. When I plug the hard disk in, the 3 partitions automatically mounted under /media. So far so good. I can read and write to files, or mkdir, etc on these partitions. But I can't do chmod/chown on any of the files/directories on these partitions. The owner:group always myself, and the mode are always 700 for directories and 600 for files.

I have another partition on internal harddisk also mounted. That partition works fine. I looked the output of mount command, the only difference between mount options is that there is one extra 'default_permissions' on the external hard disks.

Anyway I can set the owner:group and mode on these files and directories.