Your command:
Code:
chmod -R 777 /media/ldm/A10_2
run with sudo permission would fix the issue, because it would allow 'others' to rwx.
I think more traditionally, you could use groups; there should be an 'ldm' group that got created when you created the 'ldm' user. Add a10 to this group with usermod or use System Settings > Users and Groups.
Then make sure that all the files on the drive are owned by the ldm user and the ldm group, and change the permissions to 770. a10 should be able to rwx through the group permission.