mlw17

Q: External hard drive not showing up

I am using a seagate backup plus portable drive with my macbook pro running el capitan. When I plugged it in this morning to transfer some files it took a few tries but eventually it mounted, but then it wouldn't allow me to modify any files in the drive (couldn't delete or add files). I ejected it, restarted my computer, and now the drive won't show up in finder at all. I've had this drive for about 2 years during which time it's been working perfectly. I mostly use it with my TV which has been recognizing the files just fine. It's listed in disk utility but the option to mount is grayed out. Please help! This has never happened before and I've been googling for hours trying to find a solution

MacBook Pro (13-inch Mid 2012), OS X El Capitan (10.11.4)

Posted on Apr 25, 2016 8:17 AM

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Q: External hard drive not showing up

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  • by macjack,

    macjack macjack Apr 25, 2016 8:23 AM in response to mlw17
    Level 9 (55,682 points)
    Mac OS X
    Apr 25, 2016 8:23 AM in response to mlw17

    It sounds like the drive is failing or failed. All mechanical drives will fail sooner or later.

    Try this...

    Launch/Utilities/Terminal and copy & paste this command at the prompt:

    diskutil list

    Press return.

    If it sees the disk, note the number of the disk (far left column) you want to mount.

     

    Then, enter this command:

    mount /dev/(number of disk)

    Put in the number no parenthesis.

    Press Return.

     

    Also might try

    mount force /dev/(number of disk)


  • by mlw17,

    mlw17 mlw17 Apr 25, 2016 9:26 AM in response to macjack
    Level 1 (8 points)
    Notebooks
    Apr 25, 2016 9:26 AM in response to macjack

    well shoot. my last hard drive lasted me ~10 years and the only reason I replaced it was bc I wanted a portable one how will I be able to transfer all my data from this possibly dead HD to a new one??

     

    I tried those commands and neither one was successful ...

    mount /dev/ gives me an error message of "unknown special file or file system"

    mount force /dev/ is giving me an error message of "you must specify a filesystem type with -t"

  • by KimUserName,

    KimUserName KimUserName Apr 25, 2016 10:36 AM in response to mlw17
    Level 4 (1,400 points)
    Notebooks
    Apr 25, 2016 10:36 AM in response to mlw17

    Have you recently upgraded to El Capitan?

    Was it working on this computer?

     

    Try connecting it to another Mac and see if you can see it.

    Go to Applications > Utilities > Disk Utility and see if you can see it.

    If you can see it maybe you can try to repair it.

  • by KimUserName,

    KimUserName KimUserName Apr 25, 2016 10:57 AM in response to mlw17
    Level 4 (1,400 points)
    Notebooks
    Apr 25, 2016 10:57 AM in response to mlw17

    If you can't connect to the hard drive and you are pretty sure it is dead, and you have important information on it:

     

    Maybe it is only the electronics between computer and hard drive.

    See the following link; Apple Support Communities -Your dead external hard drive is likely fine! by PlotinusVeritas: Your dead external hard drive is likely fine!

     

    I suggest that you remove your external hard drive from its case and install it in an enclosure OWC external case or using a USB to SATA adapter USB to SATA adapter and connect it to your MBP via USB.

     

    Kim

  • by macjack,

    macjack macjack Apr 25, 2016 12:41 PM in response to mlw17
    Level 9 (55,682 points)
    Mac OS X
    Apr 25, 2016 12:41 PM in response to mlw17

    mlw17 wrote:

     

    I tried those commands and neither one was successful ...

    mount /dev/ gives me an error message of "unknown special file or file system"

    mount force /dev/ is giving me an error message of "you must specify a filesystem type with -t"

    You need add the disk number to those commands.

  • by mlw17,

    mlw17 mlw17 Apr 25, 2016 1:46 PM in response to macjack
    Level 1 (8 points)
    Notebooks
    Apr 25, 2016 1:46 PM in response to macjack

    yes, I did that. those were the error messages when I used those commands with disk2s1

  • by macjack,

    macjack macjack Apr 25, 2016 3:53 PM in response to mlw17
    Level 9 (55,682 points)
    Mac OS X
    Apr 25, 2016 3:53 PM in response to mlw17

    OK, then you should follow Kim's advice. Although, it does sound like a dying or dead drive.