change permissions on mac backup external hard drive

execute/search only if the file is a directory or already has execute permission for some user (X).

Man chmod says about the capital X versus lower-case x option: So, that leads me to my recommendation: give full permissions to everyone ( -a, or 'a'll), but only set the executable bit (ie: use +X, NOT +x) if it is either a directory, OR already set for one or more of 'user', 'group', or 'other', like this: sudo chmod -R a+rwX /media/username/nameofdrive Better still #1 (or best, if you DO need write permissions for everyone) for files ON an external drive You don't want to arbitrarily mark every single file as executable, as that can pose a security risk, and also be annoying when every time you double-click a text file to open and edit it, it asks you if you'd like to run/execute it. So, that leads us to this solution: just give full permissions to these files to everyone: sudo chmod -R 777 /media/username/nameofdriveīUT, that also marks ALL files as executable, which doesn't really make sense. Sometimes better for files ON an external drive Having the same groupname is okay if it is consistently the same people using the drive, and they all add themselves to the same group with: usermod -a -G groupnameīUT, if the groupname doesn't exist on one system, and just shows up as a number, such as 5000, when you look at it with ll ( ls -alF), then you can't easily add yourself to the same group because usermod -a -G 5000 produces this error: $ usermod -a -G 5000Ģ. Having the same username only works if it is the same person, so that doesn't always make sense. This works: recursively ( -R) change the username (the part before the colon :) and groupname (the part after the colon :) to your username: sudo chown -R username:username /media/username/nameofdriveīUT, the problem with this is that it makes the external disk difficult to share between multiple usernames and/or on multiple computers, because each person on each system who needs access to these files must either have the same username, or must be part of the same groupname.

Ok technique for files ON an external drive, but the correct technique for files you just copied onto your computer FROM an external drive

Change permissions on mac backup external hard drive