El Capitan Partition Drive

Itching to run the latest macOS beta, but don’t want to upgrade your primary Mac installation with a beta release? You’d be wise to carefully consider the prospects of running a beta release as a daily driver. That said, it is possible to run beta software on your primary machine without compromising your current installation.

By creating a small test partition on your primary drive, you can create a great landing space for the beta. Read and watch our walkthrough to see how easy it is.

Creating a different disk partition to install beta software

In this post, we will take the example of installing a beta version of OS X El Capitan, but note that the concept is the same regardless of what you are trying to install on that new partition.

Step 1: Download the beta software you want to install.

Step 2: Open Disk Utility.

Step 3: Select your hard drive and click the Partition tab.

Step 4: Click the ‘+’ sign to create a new partition.

Step 5: Resize the partition using the drag handles to the desired size. I used 35GB, and was fine, as OS X El Capitan only takes around 12-13 GB for installation

Step 6: Name your new partition El Capitan, or whatever you see fit.

Step 7: Ensure the Format is Mac OS Extended (Journaled).

Step 8: Click Apply and click Partition to create your partition.

Step 9: Close Disk Utility.

Step 10: Launch the OS X 10.11 El Capitan installer.

Step 11: Click Continue → Agree → Agree → Show All Disks… and select your El Capitan disk and click Install

Step 12: If requested, input your administrator password

Your computer will now restart. Once it reboots, the installation will proceed on your new partition. The installation does take some time, like a normal installation, so just be patient. Once the installation completes, go through the normal OS X setup process to complete the initial setup.

Once the installation and setup is completed, you’ll be able to boot between your primary installation and the new one containing the beta software.

Would you consider installing a beta version of an operating system on a secondary test partition?

See also: 

  • I’ve been using a second partition to test new OSes since Mountain Lion. It’s really convenient, and prevents potential damage to my primary workspace.

  • Fredric Andersson

    I did this with the Yosemite beta. Unfortunately, I cannot remove the Yosemite partition, so I wouldn’t say partitioning is 100% safe.

    • Joshua The-Legend Wiebe

      What do you mean you can’t remove it? Just add a partition to Yosemite (preferably mountain lion) and remove it from there.

    • Erase first then delete, it’s detailed in a newer iDB post.

      • The problem is that you can remove the test partition but you can’t resize the original Macintosh HD partition to its initial size.

      • I encountered similar problem in the past, and I solved it using “diskutil” command. First resize the logical volume (CoreStorage), then resize the partition inside it. I suspect that it has something to do with FileVault.

      • Fredric Andersson

        The option to remove the partition is still grayed out. Trust me, I have tried everything.

      • Run “diskutil list”, do you see a second recovery partition just before the free space? It might be the cause, you can try to remove it using diskutil.

      • Fredric Andersson

        How exactly do you remove it using diskutil?

      • http:/ /apple.stackexchange .com/questions/50374/can-i-remove-recovery-hd-partition

  • n0m0n

    How do you boot into a secondary OS?
    Would it be an option at startup?


    • That_Fruitarian

      Hold down the option key when booting or select it in system preferences under startup disk.

  • n0m0n

    Where can I find El Capitan clearly I’m not a developer.


  • Nepali Kancha

    Can I create the same partition for OSX Yosemite? I am using Mt. Lion at the moment. Thanks

  • ivan

    i use separate hard drives for all my testng of newer OSes – it takes 10% of energy to avoid a problem than to fix it !! also i upgrade a clone of my HD to ‘test’ all my other sfw ! if there is an issue i can just reformat the test hd !