HT201909: Format external drives to Mac OS Extended before using with Aperture

Learn about Format external drives to Mac OS Extended before using with Aperture
matthewfrombristow

Q: How do get past the error: "partition failed: couldn't unmount disk"

My external hard drive is not formatted properly and is stuck where it can only read files and not write. Thus, I am unable to add files to my external drive. There is no option when I choose to get info to unlock the sharing and permissions and that area has no other option it simply says, "you can only read." I found an apple post showing how to essentially erase and re-format to MAC OS X extended but then I get the following error listed below. Here is what comes up when I try to re-format my hard drive...I have tried both ways, see below:

 

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Screen Shot 2015-08-29 at 10.24.22 PM.png

MacBook Air, OS X Yosemite (10.10.5), null

Posted on Aug 29, 2015 7:30 PM

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Q: How do get past the error: "partition failed: couldn't unmount disk"

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