Step-by-Step Guide: How to Change Permissions on External Hard Drive Mac

External hard drives are essential for expanding storage and backing up data. However, a common frustration for Mac users occurs when they connect a drive—perhaps one used previously on a Windows PC—and find they are locked out. You might be able to view files, but you cannot edit, delete, or copy new data to the disk. You are essentially trapped with "Read-Only" access.

When this happens, users often search for how to change permissions on external hard drive Mac. While this sounds like a simple settings tweak, the reality is often more complex. The issue might be a simple checkbox in Finder, a corruption issue, or, most commonly, a file system incompatibility (NTFS) that macOS cannot handle natively.

This authoritative guide will analyze why you are denied access and provide 5 proven methods to fix read write permissions on an external hard drive Mac. We will cover everything from using professional software to advanced Terminal commands and system formatting.

Why Is It Hard to Change Permissions on My External Drive?

Before attempting to fix the issue, you must diagnose the root cause. If you try to fix read only external hard drive Mac issues using the wrong method, it won't work.

There are three main reasons why your Mac says "Permission Denied":

# 1. The NTFS Barrier (Most Common): If the drive was formatted on Windows (NTFS), macOS allows you to read files but blocks you from writing. Crucially, you cannot change permissions on an NTFS drive using Mac’s native settings. The "Sharing & Permissions" tab will simply say "You can only read," and it won't let you change it.

# 2. Ownership Conflicts: If the drive is formatted for Mac (APFS or HFS+), but was created on a different Mac with a different user account, your current computer may not recognize you as the "Owner," locking you out.

# 3. Disk Corruption: If the drive wasn't ejected properly, macOS may mount it as Read-Only to protect the data from further damage.

Method 1: Best Fix for Windows Drives – PartitionAssistant NTFS for Mac

If your external drive is formatted with NTFS (which is standard for most WD, Seagate, and Samsung drives), checking the "Get Info" tab to change permissions will fail. macOS simply does not support writing permission changes to the NTFS file system.

Instead of reformatting the drive (and losing all your data), the professional solution is to use PartitionAssistant NTFS for Mac. This tool acts as a bridge, instantly granting your Mac full Read-Write privileges without altering the file system.

PartitionAssistant NTFS for Mac is a newly released, powerful utility designed for seamless cross-platform management.

Grant Permission Instantly: It overrides the native read-only limitation, allowing you to read, write, delete, rename, and move files on NTFS drives directly.
Broad Support: It works with HDD, SSD, USB, SD, and CF cards.
Apple Silicon Ready: Fully optimized for macOS 12 and later, running natively on Intel and Apple Silicon (M1/M2/M3) Macs.

Free Download

100% Secure

Note: You need to configure the Security Policy in iOS Recovery Mode. macOS can only read NTFS partitions by default, not write directly to them. To write data to an NTFS partition on macOS, you need to use a third-party NTFS driver.

Step 1. Install and run PartitionAssistant NTFS for Mac and connect your target external hard drive.

Step 2. All external drives will be mounted and listed. Now you have permissions on external hard drive Mac.

Step 3. Select the drive you want to operate and click "Open". 

Now you can copy files on your Mac and click "Paste Item" to modify.

And you can also copy, delete, and rename files on the external hard drive.

After all operations are complete, please click "Eject" to disconnect the external hard drive from your Mac. But the permissions are enabled, you can still access your NTFS on your Mac.

Bonus Feature: The tool includes a "Safe Eject" button. Using this ensures that when you unplug the drive, permissions don't get corrupted for the next time you use it.

Method 2: Ignore Ownership on This Volume (For Mac Drives)

If your drive is formatted with a Mac file system (APFS or Mac OS Extended), the issue is likely that the specific user account on your Mac doesn't "own" the files. You can force the system to ignore these ownership rules.

Step 1. Ensure the drive appears on your desktop or Finder sidebar.

Step 2. Right-click (or Control-click) the drive icon and select Get Info (or press Cmd + I).

Step 3. Scroll to the bottom "Sharing & Permissions" section. Click the Padlock icon and enter your administrator password to unlock changes.

Step 4. Look for a checkbox that says "Ignore ownership on this volume." Check it.

Note: If this option is missing, your drive is likely NTFS, and you must use Method 1 or Method 5.

Step 5. Close the window. You should now have full access to the drive.

Method 3: Change Permissions via Terminal (Advanced)

If you are comfortable with command lines, you can force the system to change file attributes. This is useful for specific files that are locked.

Warning: Be careful with Terminal commands.

Step 1. Open Terminal (Applications > Utilities).

Step 2. Type paste sudo nano /etc/fstab (ensure there is a space at the end).

Step 3. Drag the external hard drive icon (or the specific folder) from Finder into the Terminal window. This creates the correct path.

Step 4. Press Enter and type your admin password.

Step 5. Type the following command for the fstab file. LABEL=NAME none ntfs rw,auto,nobrowse

Note: Insert the actual name of your external drive instead of "NAME."

Method 4: Repair Disk Permissions via Disk Utility

Sometimes, permissions become "scrambled" due to file system corruption. Disk Utility can scan the drive and repair these logical errors, restoring your access.

Step 1. Open Disk Utility (Cmd + Space, type "Disk Utility").

Step 2. Select your external hard drive from the sidebar.

Step 3. Click the "First Aid" button in the top toolbar.

Step 4. Click "Run".

Disk Utility will lock the drive, check the partition map, and repair any corruption that might be forcing the drive into Read-Only mode.

Method 5: Reformat the Drive (Destructive)

If you do not want to use third-party software (Method 1) and the drive is NTFS, your only native option to fix permissions permanently is to erase the drive and format it to a file system Mac fully supports, like exFAT or APFS.

Important: This will delete ALL data on the drive.

Step 1: Backup Data (Crucial)

Since the drive is Read-Only, you can copy files off it, but you can't modify them.

Tip: If the connection is unstable, use PartitionAssistant NTFS for Mac (from Method 1) to stabilize the connection and mount the drive properly so you can back up your files without errors.

Step 2: Format the Drive

1. Open Disk Utility. Select the external drive.
2. Click Erase.
3. Choose a Format:

• exFAT: Choose this if you want to use the drive on both Mac and Windows.
• APFS: Choose this if you only use Macs.

Now, click Erase. Once finished, the new empty drive will have full Read/Write permissions natively.

To Sum Up

When you need to know how to change permissions on external hard drive Mac, the solution depends entirely on the file system. If the drive is Mac-formatted (APFS/HFS+), use the "Ignore Ownership" tick box in Finder or run First Aid in Disk Utility.

If the drive is Windows-formatted (NTFS), native settings won't work. The most efficient, non-destructive solution is PartitionAssistant NTFS for Mac. It acts as a bridge, instantly enabling read-write permissions without the need to erase your valuable data.

Free Download

100% Secure

FAQs

Q1: Why is the "Ignore ownership on this volume" option missing?

A: If this option is missing in the "Get Info" window, it usually means your drive is formatted as NTFS or exFAT. These file systems do not support macOS ownership flags in the same way APFS does. For NTFS drives, use PartitionAssistant NTFS for Mac to enable write access.

Q2: Can I use Terminal to fix permissions on an NTFS drive?

A: No. Standard chmod commands will fail on an NTFS drive because macOS mounts the entire volume as Read-Only at the driver level. You must use third-party software to change how the drive is mounted before you can modify files.

Q3: Is it safe to change permissions to "Everyone: Read & Write"?

A: On a personal external drive, yes. However, be careful doing this on system folders. Giving "Everyone" full access means any user on any computer can modify or delete your files.