External HD mounts but doesn't display in Finder

Discussion in 'Mac Accessories' started by pfut0002, Oct 14, 2005.

  1. pfut0002 macrumors newbie

    Joined:
    Oct 14, 2005
    #1
    I was messing around with the ownership & permissions on my external HD and I think I may have switched it to no read & write.

    Now when I plug the HD in, it shows up in Disk Utility and System Profiler but not in Finder. I've verified and repaired and neither of those things seem to help.

    I'm not sure if what I did screwed it up or not.

    I have some pretty important stuff on the HD. Do I have to reformat? Is there any terminal command or somthing that I can do to get into the HD?

    Thanks for any advice.
     
  2. mad jew Moderator emeritus

    mad jew

    Joined:
    Apr 3, 2004
    Location:
    Adelaide, Australia
    #2
    In the Finder, go to the Preferences and make sure there is still a tick next to Hard Disks in the General section and in the Sidebar section too.
     
  3. mrichmon macrumors 6502a

    Joined:
    Jun 17, 2003
    #3
    There is no such thing as "hard drive" permissions. But what you may have done is set the files and folders on the drive to no read & no write. Don't do that! :)

    If this is the case then that could explain the behavior you are getting.

    First check the finder preferences... click on the desktop then from the menu select "Finder->Preferences" go to the General tab and make sure that "Hard Disks" are selected to display on the desktop.

    Then, the easiest way to resolve the problem is to copy the files off the drive and reformat it. If you have space to temporarily store the files on your main hard drive then you will not loose the files. But first you need to change the permissions to something that will let you copy the files off the external drive.

    Plug in the external drive and open a Terminal window.

    Now type in the command cd /Volumes and hit enter.

    Now type ls -la without the quotes and hit enter. This command lists the names of the drives mounted on your system in the last column. One of the names will be your boot drive displayed as "system -> /" if "system" is the name of your boot drive. The other drive listed should be the name of your external drive.

    If there is only your boot drive listed then you have bigger problems with the drive. In this case type in the command mount and press enter then copy and paste all of the output into the forums and I'll see if I can help further.

    So, assuming that you had two drives listed from the ls command, type in cd "external_drive_name" and press enter.

    Now type in the command ls -Fla this should show a listing of the files and folders at the top level of your external drive. If it does not then do not continue following these instructions. If you continue without seeing the list of files and folders on your external drive then you could hose your system.

    Assuming that you can see the list of files on your external drive, look at the left-most column from the ls -Fla command. The folders should be listed with something like "drwxr-xr-x" in the first column. The important part is the "rwx" as the 2nd, 3rd and 4th character. If you have messed up the permissions then the directories are probably listed as "d---------".

    Files at the top level should be listed as "-rw-r--r--" or similar. The important part is the "rw" in the 2nd and 3rd characters. If you have messed up the permissions the files will probably be listed as "----------".

    If, and only if the directories are there, but listed with something like "d---------" and the files are listed as something like "----------". You can set the permissions so that you can copy the files off by running the following command. First ensure that you are in the right place by running the command pwd and pressing enter. The output should be "/Volumes/name_of_your_external_drive" where "name_of_your_external_drive" is the name of your external drive that used to display on the desktop. If this is the case then type in sudo chmod -R u+rwx * and press enter. You will be prompted for your administrator password. Type it in and wait until the command completes. It may take a while if you have lots of files on the external drive.

    Now, quit out of the terminal application and go into Disk Utility and highlight your external drive. Click on the "unmount" button. Now unplug your external drive.

    When you plug the drive back in it should be displayed on your desktop and you should be able to copy your files off the drive. Copy them to a tempory location on your boot drive and then reformat your external drive. When the external drive is re-formated copy your data back onto it.

    :D
     
  4. moviegourmet macrumors newbie

    Joined:
    Jun 26, 2008
    #4
    Thank you so much! This answered my problem. I have read and printed out so many instructions, but this tip wasn't included. All of my PC files are now on my iMac.

    I've never set up a computer before and I've used this forum quite a bit for help. Thanks to all!
     
  5. rochmann macrumors newbie

    Joined:
    Nov 16, 2009
    #5
    I Change the permissions for my external hard drive to NO ACCESS, now I can not mount

    I Change the permissions for my external hard drive to NO ACCESS since I'm sheering some folder with other users and now I can not mount it or see it in the finder.

    It shows up in Disk Utility and System Profiler but not in Finder. I've verified and repaired and neither of those things seem to help.

    Is there any terminal command or something that I can do to get into the HD to change the permissions?.

    I have all my office back up docs on that HD.

    Please Help!!
     

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