I just got my Macbook here, and I got a USB with Yosemite 10.10.

I opened up the Macbook, took out the old one, and put the SSD inside.

My SSD fits perfectly (Samsung SSD 850 EVO 250GB).

Then I plug the USB thumb drive in, and then boot the computer up, and holding the ALT (OPTION) key down. Then I came into the drives that I can boot from. I couldn't see my SSD there, then I took the thumb drive(8GB), and then I began to install Yosemite, after I choose the language, I need to choose where I need to install Yosemite. The hard drive, didn't show up there either.

I get in Disk Utility and find out that my hard drive, isn't formatted, I just want to format it to Mac OS Extended Journaled, I chose it, and clicked erase and when I did that, I got this error:

Erasing the disk failed, Erasing the disk failed with error:

Formatting the file system failed.

I translated the error from Danish, so it could be worded differently on the English version of Disk Utility.

  • 2
    You could try putting the SSD into an enclosure (or getting a SATA to USB connector), plug it in and try to format the drive then.
    – oarfish
    Jun 1, 2015 at 14:11
  • 1
    The Mac is not new, the SSD is new and never used. And the error (Erasing the disk failed, Erasing the disk failed with error: Formatting the file system failed.) was probably given on danish, so it could be another error on english computers. Jun 1, 2015 at 16:38
  • It's unclear whether you are attempting to boot from the USB drive or the SSD. What you should be doing is booting from a Yosemite installation USB drive into Disk Utility, reformatting the SSD, then installing Yosemite onto it. Is this what you attempted to do?
    – Rampant
    Jul 3, 2015 at 16:41

1 Answer 1


You have to format the SSD without using it as your primary disk.

If you're able to run Mac with the old disk, connect the SSD via external enclosure and format it (or make a clone of the running HDD). After this swap the disks, boot form installer and install OS on SSD.

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  • Try to make a copy of your actual HDD on SSD (e.g. Try using Carbon Copy Cloner). After this mount SSD as primary disk and boot. It should be fine. Otherwise open Disk Utility from recovery mode and repair the SSD. I've replaced my HDD with an SSD cloning the primary disk into the SSD, and everything gone fine. Jul 3, 2015 at 17:37

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