scottca
Level 1 (0 points)

Q: El Capitan Problem with  Disk Utility and USB Drive Partitioning

I am trying to set up a USB thumb drive to have GUID partition so that it can be bootable.

When I go into disk utility, the disk does not appear as a physical disk with a volume below it. Instead it only shows the volume.

I can not change the partitions without being able to select the physical disk.

 

In the screenshot below you will see I have two external usb drives.

The first one "UFD 2.0 Silicon" appears as a physical disk with the volume "Install OS X El" below it and I can choose how to partition this one. No problem.

 

The second USB drive, which I am having trouble with, only shows the volume "USB DISK" but does not have a physical device listed above it that I can select.

As you can see from the screenshot, it is listed as "external physical volume osx extended" but there is no "external physical disk" listed above it.

 

 

When I try erase, it does not give me the dialog box for "Scheme" (see second image) to select the partition type for the disk, it treats it like a volume.

Disk Utility only gives the Partition Scheme option for physical disks.

How can I fix this disk so that I can set it up with a GUID partition?

Screen Shot 2015-10-12 at 3.36.57 PM.png

Screen Shot 2015-10-12 at 3.49.08 PM.png

Posted on Oct 12, 2015 12:54 PM

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scottca

Q: El Capitan Problem with  Disk Utility and USB Drive Partitioning

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  • Helpful answers

  • by ptam89,

    ptam89 ptam89 Nov 11, 2015 8:40 AM in response to scottca
    Level 1 (0 points)
    Nov 11, 2015 8:40 AM in response to scottca

    I was able to get around this issue by booting into fedora linux and using gparted to set the partition table to GPT and creating one partition of hfs+. Then I could see the partition button lit up.

  • by CraigarJ,

    CraigarJ CraigarJ Jan 5, 2016 2:35 PM in response to scottca
    Level 1 (0 points)
    Jan 5, 2016 2:35 PM in response to scottca

    I was able to resolve this issue by reformatting my HD ( via Windows 7).  Afterward el Capitan / Disk Utility was able to partition it.

  • by davidatoakside,

    davidatoakside davidatoakside Jan 8, 2016 9:17 AM in response to CraigarJ
    Level 1 (0 points)
    Jan 8, 2016 9:17 AM in response to CraigarJ

    Same problem with any USB devices with more than one partition. Nothing works under El Capitan!  Not only disk utility, but also Finder, Terminal commands, and Applications are all affected.  That makes it more difficult for me to prepare media for Raspberry Pi - USB sticks and SD cards.  But on the same Macbook I have Ubuntu running in a Parallels virtual machine, and that (fortunately) works OK with these multi-partition USB devices.

  • by Guoxuan,

    Guoxuan Guoxuan Jan 28, 2016 9:41 PM in response to davidatoakside
    Level 1 (4 points)
    Mac OS X
    Jan 28, 2016 9:41 PM in response to davidatoakside

    IS this bug solved?

  • by cumhuryalcin,

    cumhuryalcin cumhuryalcin Jan 28, 2016 9:56 PM in response to Guoxuan
    Level 2 (156 points)
    iCloud
    Jan 28, 2016 9:56 PM in response to Guoxuan

    i walked around the problem with Rufus first to format exfat then reformat agin from disk utility

  • by davidatoakside,

    davidatoakside davidatoakside Jan 30, 2016 1:57 AM in response to Guoxuan
    Level 1 (0 points)
    Jan 30, 2016 1:57 AM in response to Guoxuan

    Solved? No.  I work around it with Ubuntu.  And though the earlier 'ApplePi-Baker' failed to work with El Capitan for preparing disk images, the update to 'ApplePi-Baker-2' is fine.  (The creator's blog outlines the story of what he had to do to accommodate the El Capitan changes)

  • by --ADH99--,

    --ADH99-- --ADH99-- Apr 20, 2016 11:47 AM in response to scottca
    Level 1 (4 points)
    Apr 20, 2016 11:47 AM in response to scottca

    Hi,

    I had this same problem but I managed to fix it by:

     

    Formatting the disk using the format exFAT at first

    Then formatting the disk again in the format you want (you should now be able to choose the scheme too)

    I then chose OS X Extended (case sensitive, journaled, encrypted)

    Chose the scheme GUID Partition Map

    Setup my password (blah blah blah...)

    AND DONE!!

  • by Gabriel (Andreaux),

    Gabriel (Andreaux) Gabriel (Andreaux) Jul 29, 2016 2:03 PM in response to scottca
    Level 1 (4 points)
    Jul 29, 2016 2:03 PM in response to scottca

    Hi there,

     

    Here's my quick fix:

     

    1. Open  Disk Utility and select your USB stick.

    2. look for the "Device:" label on the bottom left and note which disk your USB stick is. I am using disk5 in my example.

    3. Open up Terminal and issue the following command where you replace "disk5" with your disk and Installer with whatever name you want your partition to be called.
      sudo diskutil partitionDisk disk5 1 jhfs+ Installer R

      WARNING! THERE IS NO CONFIRMATION AFTER THIS. IT WILL ERASE EVERYTHING ON YOUR DISK.

      (The command tells diskutility to partition the disk named disk5 and create 1 journaled hfs+ partition named Installer and use all the available ("R for remaining") space.)

    4. Disk Utility should now recognise your USB stick correctly.


    Hope this helps.

  • by GioMan,

    GioMan GioMan Oct 18, 2016 8:03 AM in response to --ADH99--
    Level 1 (4 points)
    Oct 18, 2016 8:03 AM in response to --ADH99--

    You win.  Thank you