This post will show you how to enable or disable permissions on a HFS+ volume and also how to check if a volume had the permissions enabled or not.
By default when you create a HFS+ filesystem it will have the permissions/owners disabled. I'm using a macmini for backing up files from a linux system and if I want the backup to be fully consistent with the source I need filesystem permissions.
Another problem is that using rsync between a permission based and a non permission based filesystem is useless because all files will always be out of sync.
Check permissions
vsdbutil -c /Volumes/YourVolume
it will "Permissions on '/Volumes/YourVolume' are enabled ( or disabled ) of just "No entry found for '/Volumes/YourVolume'" which means the permissions are disabled.
Enable Permissions
vsdbutil -a /Volumes/YourVolume
Disable Permissions
Since permissions are disabled by default I don't see many wanting to disable permissions but here's how you can do it anyway:
vsdbutil -d /Volumes/YourVolume
I guess this is really useful only when you want to distribute a dmg image which currently has permissions enabled.
Distributing images with permissions enabled doesn't make much sense because the user that will open the image may have a different id then the user id that owns the files in the image so he may not be able to access the files inside the image.