Hot answers tagged external-disk
MacBook Pro (15-inch, Late 2011) Every USB hard disk, flash drive, or SD Card I have ever connected to this computer occasionally reports this error when the computer wakes up. It doesn't matter whether the computer went to sleep after non-use, closing the lid, or low battery hibernation. The only workable solutions I know of are to disable sleep, never ...
Means that you and every body have permissions to write over directories. On your mac drive only you have perms to write inside. Note that you folder on mac drive have perms drwxr-xr-x, and your external hd have drwxrwxrwx. How to Set File Permissions in Mac OS X
The @ at the end of the name means that the Finder has extended attributes OTHER than an ACL but might also be all manner of other things (Finder info for one). You can see what attributes are by ls -le@.
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