I have 10.9.4 with a usb external (2tb) disk, formatted with Macos Journalled format. The drive is also a time-machine destination.

I am:

  • unable to cmd-drag files to move them to another disk (they copy)
  • unable to select multiple files and create a new folder from the selection
  • unable to mkdir on the drive
TimsMacBookAir:~ tim$ cd /Volumes/2TB/
TimsMacBookAir:2TB tim$ mkdir test
mkdir: test: Permission denied

I'm guessing there's permission errors. Here's the ls -l on /Volumes

TimsMacBookAir:Volumes tim$ ls -l
total 72
drwxrwxr-x   37 tim   staff   1326  7 Jul 10:19 1TB
drwxrwxr-x  319 root  wheel  10914  7 Jul 10:51 2TB
lrwxr-xr-x    1 root  admin      1  1 Jul 14:20 Macintosh HD -> /

I'm guessing that since the drive is owned by "root" and group "wheel" that is the issue. What does it mean? Can I just chown -R tim:staff it without stuffing anything up (e.g. my Time Machine backups)?

1 Answer 1


This might be a silly question but are you sure that the drive is mounted read-write.

From memory, if you type in "mount" in a Terminal it should tell you if the drive is mounted read-only as one of the properties in brackets after the drive. Or you could right-click the drive in the Finder and choose Get Info from the context menu and check "Sharing & Permissions" at the bottom of the Info window. I think it'll tell you there if the drive is mounted read-only.

  • yes, it is mounted read write.
    – frumbert
    Commented Jul 7, 2014 at 2:19

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