What are the default owner and group permissions on an external volume? This is for data only.
For MacOS (née OS X), the default owner and group permissions on a freshly formatted external drive are (in several parlances):
For example, I just hooked up an external drive, my username is mrcook, so the permissions shown for the drive via Terminal and the
ls -pal command are:
drwxrwxr-x mrcook staff
To change permissions on an external drive with MacOS, run
chmod to change the permissions like read, write, etc. Run
chown to change the owner and group. Both
chown can be run without using
sudo if you are the administrator of your Mac.
You can read more about
chmod and 'chown` on the extremely useful SS64 website which has a list of (most?) MacOS shell commands and their switches.
Update to add information about the "ignore ownership on this volume" checkbox option in the Finder's Get Info
The "ignore ownership on this volume" is checked by default so "everything just works" as Apple likes to say. This option sets the permissions as described above. However, if you uncheck the "ignore ownership on this volume" option, the drive permissions change to
I was able to use
sudo vsdbutil -c /Volumes/DiskName recommended by this Mac OS X Hints page from 2002 to check the status of the permissions on the drive. The other suggestions worked as well:
sudo vsdbutil -a /Volumes/DiskNameto check the option
sudo vsdbutil -d /Volumes/DiskNameto uncheck the option
YMMV though depending on the version of MacOS you are using. I highly recommend this previous question on how to change "ignore ownership on this volume" from the command line because the changes made via
vsdbutil may not stick after mounting and remounting the drive.