I have a Western Digital 2.5 TB hard drive. (Model WD25EZRS) It's connected through an external USB dock to my iMac, running Mac OS X Mavericks.

In Disk Utility there are two volumes, totaling 2.5 TB but separate as 2.2 TB and 300 GB. How do I format / partition / group the volumes to use this was one large drive with one partition?

Adding image http://mattmanuel.brace.io/diskutil_for_stackexchange.png

  • Do you need to preserve any data on either partition of the drive? – njboot Jun 14 '14 at 3:06
  • Nope. It's a brand new disk. – Matt Manuel Jun 14 '14 at 20:54

Open Disk Utility (in Application/Utilities). Locate your harddrive on the left. Not one of the partitions, but the whole harddrive. Then click Partition in the tabs on the right (see screenshot). Then click on the the dropdown menu (where Current stands in the screenshot), and select 1 partition (see screenshot 2). Click apply, and wait. Then you have 1 volume.

Note, your data will go lost. Save it somewhere else. Then you can safely put it back, after it has become 1 volume.

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  • I added a screenshot of my Disk Utility. Notice the bottom two drives are the same physical disk. – Matt Manuel Jun 14 '14 at 20:58
  • Okay. Than it isn't solvable this way indeed. I won't delete it though, as it will work 99% of the tjme – Mathias711 Jun 15 '14 at 7:30

I just figured it out. It's the USB Docking station that I'm using. It has a limit of 2 TB for the drives that it supports.

monoprice link

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