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BJB Productions

macrumors 65816
Original poster
Nov 10, 2008
Hi all--

Today I purchased and received the OWC SSD Data Doubler with a 6g SSD. Information on how to go about getting it to work after installing was very sparse.

After reading a lot it was very clear that I should NOT install the SSD in the data doubler, due to speed. (I have an early 2011 MBP) So I installed the SSD in the main hard drive bay and my old HHD in the data doubler. I booted up to my old HDD so I could clone to the SSD.

However, when I try to format the SSD, I get this error in Disk Utility:
Partition failed
Partition failed with the error:

Couldn’t open device.

What am I doing wrong? I could not seem to find any information on this.

Thank you..and be nice. I'm a novice with this.


macrumors 65816
Aug 24, 2011
Wirelessly posted

The error you are getting is related to disk access which means you are trying to format the current boot volume or it's locked by NTFS. Sometimes a faulty physical connection can throw this error.

If you are using Lion boot to the recovery partition by holding option or c or Command + r at start up bong. From there use disk utilities to delete the existing partition and re-format the SSD. Make sure you are selecting the proper disk. OWC drives will nicely display the name not cryptic part number like Western Digital.

If that is successful, restore your hard drive to the formatted OWC SSD using disk utilities while still in the recovery partition. This will copy the recovery partition as well.

If that is not successful, check the connection. Next option is to try to format using a USB or eSATA adapter like the Seagate Freeagent GoFlex cables on a Windows machine to FAT32.


macrumors newbie
Mar 20, 2013
SSD with Intel Mac - Couldn’t open device. Fix

I also had the problem. Fixed by attaching the SSD to a USB drive caddy. The system then recognised the drive and I was able to format it connected to USB.
It then appeared once transferred into the ICY DOCK and into a spare drive bay for use as an internal SATA drive.
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