You finished updating your Mac and were in the mood to transfer some files to a Toshiba external hard drive. Surprisingly, the drive won't accept your files. In an instant, you know the Toshiba external hard drive has somehow become read-only on Mac.
The story may be different, but the problem of Toshiba external hard drives being read-only on Mac is commonly faced by many users. They are unable to copy, transfer, delete, or save to the read-only drive on a Mac.
Luckily, the issue can be easily resolved. In this guide, we'll cover the 5 best solutions to fix a Toshiba external hard drive read-only on Mac.
Ways to try when your Toshiba external hard drive on Mac is read-only:
| User Symptom / Error | Suitable Cases | Recommended Methods |
| Cannot Copy Files / Get Info Shows "Read-Only" (NTFS Format) | The drive is formatted with NTFS (typical factory setting for Toshiba Canvio Basics/Ready). You can view the contents but cannot write data. | Use iBoysoft NTFS for Mac (Find free NTFS for Mac collection) to grant full read/write access. |
| Get Info Shows "Read-Only" (Mac Native Format) | The drive is already formatted with APFS or Mac OS Extended (Journaled), but your user account lacks write permissions. | Change permissions on the Toshiba external hard drive via the "Get Info" panel (check "Ignore ownership on this volume"). |
| Time Machine Backup Disk Needs Shared Storage | The drive is dedicated to Time Machine, but you want to use the remaining spare space for everyday file storage without losing your backups. | Add a new APFS volume (safest for APFS) or partition the Time Machine backup disk (for older HFS+ formats) after a full safety backup. |
| Encrypted (Drive is locked and won't mount) | The Toshiba drive is password-protected or locked by BitLocker / FileVault, preventing the Mac from reading or writing data. | Unlock the Toshiba external drive on Mac by entering the correct decryption password or using dedicated BitLocker for Mac utilities. |
| Disk Utility Warning / Damaged File System | Disk Utility shows severe file system corruption warnings, or you simply want a fresh start and do not care about existing files. | Reformat the Toshiba external hard drive for Mac using Disk Utility (Suitable for all scenarios, but will permanently delete all data). |
Why is your Toshiba external hard drive read only on Mac?
The NTFS file system, Time Machine backups, read-only permission settings, and disk encryption are the primary reasons that render your external hard drive read-only on Mac.
Cause 1: Your Toshiba external hard drive is formatted in NTFS
If you are struggling with a Toshiba portable drive (such as the popular Toshiba Canvio series) that suddenly won't let you save files, you are likely dealing with one of two common scenarios: NTFS formatting or an incompatible NTFS driver.
Toshiba, like other mainstream manufacturers, typically caters to the majority of computer users by rolling out its devices with NTFS straight out of the box. While this makes a Toshiba portable drive instantly ready for Windows users, it also makes it read-only on a Mac. Because NTFS is Microsoft's preferred format, macOS can natively view and copy files from your Toshiba Canvio, but it cannot write a single byte of data to it without help.
If you were able to write to the Toshiba external hard drive before but were unable to write to it after a macOS update, your drive isn't broken. Instead, the update likely has changed underlying system code, rendering the old NTFS driver incompatible and reverting the Toshiba Canvio to its default, native state: read-only or even unmountable.
To change your Toshiba external hard drive from read-only to read/write, use iBoysoft NTFS for Mac!
Cause 2: Your Toshiba external hard disk is used by Time Machine
Another common cause of an external hard drive read-only on Mac is Time Machine backups. Sometimes, Time Machine will pop up notifications asking whether you want to use the drive for backups. If you agree with it, the drive will be reserved for Time Machine backups and become read-only to any other files.
Cause 3: Your Toshiba external hard drive has read-only permissions
It's also possible that the Toshiba drive has its permissions set to read-only on Mac or that you don't have ownership of it.
Cause 4: Your Toshiba external hard disk is encrypted
When an external drive is encrypted, it will appear read-only on Mac until it is unlocked.
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How to fix Toshiba external hard drive read only on Mac?
The first step to stop your Toshiba external hard drive from being read-only on Mac is to know its file system and current usage. Once you've learned the information, you can jump straight to the solution and fix it in no time.
Open Disk Utility, then select the partition of your read-only Toshiba external hard drive and check the format displayed under the disk name.
- If it says Windows NTFS, enable read/write access to NTFS with Way 1.
- If it reads APFS/Mac OS Extended (Journaled), follow Way 2 to change permissions.
- If it says FAT32/exFAT, take the steps in Way 5 to reformat the drive.
- If it's a Time Machine backup disk, use Way 3 to partition the disk.
- If it's encrypted, unlock the Toshiba drive with Way 4.
Way 1: Use a Toshiba NTFS driver for Mac
#Applies to NTFS drives
The most effective way to resolve the read-only issue on a Toshiba external hard drive for Mac is to use iBoysoft NTFS for Mac.
It's a reliable NTFS for Mac driver that grants you full read/write access to NTFS external hard drives on Mac, without data loss. Once installed, it will automatically change your Toshiba external drive from read-only to read/write on Mac, allowing you to write to NTFS on Mac.
With it, you can copy, delete, move, or save files in Finder without reformatting the Toshiba drive.
The NTFS for macOS Tahoe, Sequoia, Sonoma, Ventura, and earlier supported versions support Apple Silicon and Intel Macs. You can use it with other drive brands as well, such as Seagate, WD, LaCie, SanDisk, and Samsung.
👉 Learn the NTFS for Mac tech evolution and the iBoysoft NTFS for Mac read/write performance.
Download this Toshiba NTFS driver for Mac, select your drive, and click Open to work with it freely. (If you have an old NTFS for Mac, uninstall it first to avoid conflicts.)
Way 2: Change permissions on Toshiba external hard drive on Mac
#Applies to APFS or Mac OS Extended (Journaled) drives
File systems like APFS and Mac OS Extended (Journaled) allow users to customize permissions for different accounts. If the drive was previously owned by another user, its permissions may be modified. To set your account with read/write privileges, take the steps below:
How to change permissions on Toshiba external hard drive on Mac:
- Locate the icon of your Toshiba drive on the desktop or in Finder's sidebar.
- Right-click on it and select "Get Info."
- Scroll down to the "Sharing & Permissions" section.
- Under the message "You can only read," there should be names and privileges. (If it's blank, your drive is formatted with exFAT or FAT32, which doesn't have permissions; if you see the section but can't change permissions, it's formatted in NTFS.)
- Tap the yellow lock to unlock the setting.
- Next to your account, click the arrow and set it to Read & Write.
- Tap the action pop-up and select "Apply to enclosed items."
- Tick the box beside "Ignore ownership on this volume."
- Click the lock to save changes.
If you still can't save to the external hard drive on Mac, reformat it.
Way 3: Partition Time Machine backup disk
As we mentioned before, the Time Machine backup disk is read-only on Mac because all its space is allocated to Time Machine.
If you want to share a Time Machine backup drive formatted with Mac OS Extended (Journaled), back up your data before partitioning it, separating it from the Time Machine partition. This will force your Mac to physically slice the drive's master map, resize structural containers, and relocate existing sectors, resulting in data loss.
If it's an APFS disk, add a new APFS volume instead. This doesn't resize the drive or modify the partition map, so it won't cause data loss.
To partition the Time Machine backup disk:
- Open Disk Utility.
- Select the Toshiba external drive and click Partition.
- Click the ( + ) button to create a new partition.
- Specify its size, format, and name.
- Click Apply.
Way 4: Unlock Toshiba external drive on Mac
If your Toshiba external hard drive is encrypted, it will appear read-only when you check its permissions. To gain read and write access to it, you must unlock it by selecting it in Disk Utility and entering the correct password.
Way 5: Reformat Toshiba external hard drive for Mac
#Applies to empty or backed-up Toshiba drive
No matter which file system you have, if it's encrypted or saved for Time Machine, reformatting will fix the read-only Toshiba drive. However, it will also erase all files on the disk. So, if you decide to reformat the Toshiba external hard drive for Mac, you must back up the essential files first.
- Open Disk Utility.
- Click View > Show All Devices.
- Select the Toshiba physical disk and click Erase.
- Name it to your liking.
- Choose a proper file system.
- Keep GUID Partition Map as the scheme.
- Click Erase.
Note: If you're uncertain which file system to choose, continue reading about how to reformat external hard drives on Mac.
Also read:
FAQs
- QWhy did my Toshiba external hard drive suddenly become read-only after updating my Mac?
-
A
This usually happens because your third-party NTFS for Mac driver became incompatible with the new macOS update. Major macOS updates change system security policies and block older software extensions. To fix this, you don't need to format your drive; simply open your NTFS utility to check for software updates, or go to System Settings > Privacy & Security to re-grant the driver 'Full Disk Access.'
- QCan I change my Toshiba drive from read-only to read-write without formatting and losing my files?
-
A
Yes, absolutely. If the drive is read-only because it is formatted in NTFS (Toshiba's standard factory setting), you can install an NTFS for Mac driver. This software acts as a bridge, allowing your Mac to safely write data to the drive instantly without erasing any of your existing files. Formatting is only required if you want to completely switch the drive over to Apple's native APFS format.