Managing disk partitions is a fundamental skill for any macOS user who wants to take full control of their system. Whether you're repurposing a drive, resolving storage issues, or simply reorganizing space, knowing how to delete an APFS (Apple File System) partition can be essential. Although macOS Sierra was released prior to APFS being the default file system (which occurred with macOS High Sierra), certain users may still encounter APFS volumes if they upgraded or worked with APFS manually. This guide offers a reliable, step-by-step approach for deleting an APFS partition on macOS Sierra using the Disk Utility and Terminal applications.
Understanding APFS and macOS Sierra Compatibility
Before proceeding, it's important to understand that macOS Sierra does not natively support all the features of APFS, as it was released before APFS became the default file system. If the APFS partition was created by an external device, or if you've used third-party tools or beta versions of Sierra with partial APFS support, caution is advised.
Make sure you have successfully backed up all essential data before attempting to delete any partition. Deleting a partition permanently removes all data stored on it.
Step-by-Step Guide to Deleting an APFS Partition on macOS Sierra
Step 1: Launch Disk Utility
- Go to your Applications folder.
- Open the Utilities folder and launch Disk Utility.
- Once opened, select “Show All Devices” from the View menu to display all partitions and containers.
Step 2: Identify the APFS Partition
In the sidebar, look for the APFS container or volume you wish to delete. APFS partitions are located inside containers marked as such (e.g., “Container disk1”). Expand the container to view individual volumes.
Carefully identify the correct volume. Do not delete your main system volume if you're still running the OS from it.
Step 3: Unmount the Partition
- Select the APFS volume and click Unmount at the top of the Disk Utility window.
- Wait for the process to complete. The partition will become greyed out once unmounted.
If the volume doesn't unmount, you may need to use Terminal to force unmount it using the command:
diskutil unmount /dev/diskXsYReplace “X” and “Y” with your specific disk and slice numbers from Disk Utility.
Step 4: Delete the APFS Volume
- With the volume unmounted, click Edit from the top menu and select Delete APFS Volume.
- Confirm the deletion when prompted.
If the option is unavailable, you may need to use Terminal for removal:
diskutil apfs deleteVolume diskXsYThis command will securely remove the APFS volume from your disk.
Step 5: Reclaim the Space
After deleting the volume, the space it occupied may remain inside the APFS container. To fully reclaim the space, you can delete the container if no other volumes depend on it:
diskutil apfs deleteContainer diskXOnce deleted, you can reformat the space as needed — for example, creating a new macOS Extended (Journaled) or exFAT partition.
Precautions and Troubleshooting
Even though Disk Utility provides a graphical way to manage partitions, it’s not foolproof on macOS Sierra when dealing with APFS volumes. If Disk Utility fails to perform the operation, Terminal usually handles it more effectively. Should you see errors or if the volume won't delete, reboot into Recovery Mode by holding Command + R during startup, and repeat the process from there.
Tips to Avoid Data Loss:
- Always verify which partition you are removing.
- Maintain a complete backup of your system using Time Machine or an external drive.
- Never delete volumes unless you're sure of their purpose and origin.
Conclusion
Deleting an APFS partition on macOS Sierra can be done safely as long as you follow a systematic approach and apply caution at every step. With the steps outlined above — from identifying and unmounting the volume to deleting the container — you regain control over your disk's layout and usage.
For users still running older macOS versions, upgrading to a newer release like macOS High Sierra or later is recommended for better APFS support. Nonetheless, with terminal proficiency and care, managing partitions in macOS Sierra remains well within reach.
