How to Erase a Mac's Hard Drive Using Terminal (2025 Guide)

Erasing a Mac's hard drive using Terminal can be a faster and more flexible option than using Disk Utility. This guide explains the step-by-step process to securely erase your Mac's hard drive, including optional secure erase methods for sensitive data.

Table of Contents

• Introduction
• Step 1: Identify the Disk
• Step 2: Unmount the Disk
• Step 3: Erase the Disk
• Step 4: Secure Erase (Optional)
• Important Considerations
• Final Notes

Introduction

Using Terminal to erase a hard drive gives you more control compared to using graphical tools like Disk Utility. It's especially useful for troubleshooting, securely erasing sensitive data, or preparing a disk for a new installation.

Step 1: Identify the Disk

First, open the Terminal app and list all available drives by typing:

diskutil list

Find the disk you want to erase (example: /dev/disk2).

Step 2: Unmount the Disk

Before erasing, unmount the disk:

diskutil unmountDisk /dev/disk#

Replace # with the correct disk number. If it refuses, force unmount:

diskutil unmountDisk force /dev/disk#

Step 3: Erase the Disk

Format the drive using your desired file system:

• APFS: Best for modern macOS versions.
• JHFS+: For compatibility with older Macs.
• ExFAT: Cross-platform between Mac and Windows.
• FAT32: Older format, widely compatible but limited.

Command to erase and reformat the disk:

diskutil eraseDisk FORMAT DRIVE_NAME /dev/disk#

Example:

diskutil eraseDisk ExFAT MyDrive /dev/disk2

Step 4: Secure Erase (Optional)

If you need to securely erase data (not recommended for SSDs due to wear), use:

diskutil secureErase LEVEL /dev/disk#

Where LEVEL can be:

• 0: Single-pass zero-fill
• 1: Single-pass random data
• 2: US DoD 7-pass erase
• 3: Gutmann 35-pass erase
• 4: 3-pass random and zero-fill

Example:

diskutil secureErase 2 /dev/disk2

Important Considerations

• SSDs and flash drives: Avoid secureErase to prevent excessive wear.
• Data recovery: Secure erase minimizes but does not guarantee complete data destruction.
• Encryption: Consider encrypting your drive before wiping for extra security.
• Drive errors: Persistent problems during erase may indicate failing hardware.

Final Notes

Terminal commands offer precision and flexibility when erasing a Mac hard drive. Whether you're preparing a drive for resale, troubleshooting, or safeguarding sensitive data, following these steps ensures a thorough and secure wipe.

For more detailed examples and advanced methods, you can visit the original guide: