Unable to Verify Startup Disk Mac? What to Do?

Learn how to fix the 'Unable to Verify Startup Disk' error on your Mac. Follow step-by-step solutions, repair disk issues safely, and recover lost data with reliable tools like EaseUS. Works for Intel and M1/M2 Macs.

What Causes Mac Unable to Verify the Startup Disk

When macOS displays "Unable to verify startup disk. Try again or select another startup disk." It often appears as a critical alert during system boot or when running Disk Utility's First Aid function. This verification failure occurs when macOS detects disk inconsistencies that prevent normal operation. Many potential reasons can cause this issue:

• ⚠️File System Corruption: Both APFS and HFS+ can develop directory damage from improper shutdowns, showing errors like "invalid node structure".
• ⚠️Physical Disk Failure: Bad sectors or SMART errors trigger warnings like "the disk is about to fail", requiring immediate replacement.
• ⚠️Update Interruptions: Failed macOS updates leave partial system files, breaking cryptographic seals on Apple Silicon Macs during boot verification.
• ⚠️Improper Shutdowns: Force restarts corrupt APFS containers, often creating /DamagedFiles folders.

Verification is macOS's multi-layered integrity check examining file system metadata, directory structures, and cryptographic seals (for signed volumes).

When this process fails, macOS blocks startup to prevent data loss, though users often perceive it as an inconvenient roadblock rather than a protective measure. That's why you encounter this Mac startup disk issue.

If you need to make a copy of your startup disk to recover data, try EaseUS Data Recovery Wizard for Mac, and it can help you recover data in the Recovery Mode.

How to Fix Unable to Verify Startup Disk on Mac | 4 Ways

In this section, we'll provide multiple troubleshooting approaches, from basic First Aid repairs to advanced Terminal commands and system reinstalls, helping you restore your Mac's boot capability while preserving data. Now, let's get started!

Method 1. Fix Startup Disk Not Verify with First Aid

Because of this startup disk error code, you cannot boot your Mac as normal, so it's necessary to fix this problem in the Mac Recovery Mode.

• Intel Macs: Restart and hold Command+R until the Apple logo appears.
• Apple Silicon: Press/hold the power button > select "Options"> click "Continue".

Step 1. Select "Disk Utility".

Step 2. Choose your startup disk (The startup disk is usually the Macintosh HD) > click "First Aid".

If the First Aid option works, you will see "The operation completed successfully", which means minor corruption was fixed.

However, errors such as "overlapped extent allocation" indicate severe damage that requires advanced repair. You can move on to the next solution.

Method 2. Run Terminal Commands to Fix Startup Disk Not Verified

This method also needs to be done in the Recovery Mode:

Step 1. In Recovery Mode, open "Terminal" from Utilities.

Step 2. In the Terminal window, put in the following commands:

• diskutil verifyVolume / to diagnose issues.
• diskutil repairVolume / to fix errors.
• If unmountable: Use diskutil mount force / first.

You can share this advanced command line method on social media to help other Mac users fix this startup disk error.

Method 3. Reset NVRAM/SMC

Resetting NVRAM/SMC can resolve Mac issues like incorrect startup disk selection, display resolution problems, power/battery glitches, fan speed abnormalities, and peripheral malfunctions.

NVRAM handles system settings (volume, time zone), while SMC manages hardware functions (power, thermal, LEDs). These resets don't affect user data but restore default configurations

For Intel Macs:

• NVRAM: Restart > hold Option+Command+P+R for 20 seconds.
• SMC: Shut down > hold Shift+Control+Option+Power for 10 sec.

For Apple Silicon

• NVRAM resets automatically; SMC isn't applicable.

Method 4. Reinstalling macOS to Fix Unable to Verify Mac Startup Disk

Erasing and reinstalling the Mac is an effective way to fix Mac startup issues. But you should know that after reinstalling, you'll lose data on your Mac. So it's recommended to back up your Mac in advance.

Step 1. In Recovery Mode, select Reinstall macOS.

Step 2. There are two ways of reinstalling:

• Standard reinstall: Preserves user data while replacing system files (ideal for corruption).
• Erase-and-install: Wipes the disk entirely (use only if Disk Utility fails).

Step 3. Follow prompts; internet connection required for downloading macOS.

How to Recover Data from an Unverified Startup Disk on Mac

⚠️ Warning: Always recover data before attempting disk repairs or macOS reinstallation!

An unverified startup disk is usually in a corrupted condition. Corruption affects critical catalog files/partition tables, and hardware degradation or power failures damage logical structures

You can download EaseUS Data Recovery Wizard for Mac to recover data from a non-working Mac startup disk.

• ✅ Recovers data from unmounted/corrupted disks directly.
• ✅ Support Mac hard drive recovery in Recovery Mode or via disk image scanning.
• ✅ Automatically recover data from an unbootable Mac without any advanced recovery skills.

Check the following tutorial to restore data from your unbootable startup disk in the Recovery Mode:

Step 1. Launch EaseUS Software in Recovery Mode

Select "Utilities > Terminal" from the top menu, and enter the command sh <(curl https://d3.easeus.com/mac/boot.sh). Hit "Return". Wait for the application to open, and it will take several minutes.

Note: If the Terminal displays either "No such file or directory" or "Could not resolve host," you should verify that the command line you entered is correctly spelled, ensure your Mac has a stable internet connection, and confirm that your macOS version is not lower than macOS 10.15.

Step 2. Select the Volume on Your Mac Hard Drive

Select the volume where your lost data is stored, and click "Search for lost files". The EaseUS software will quickly locate all the recoverable data on the selected volume.

Step 3. Choose the Lost Data You Want

EaseUS software categorizes the scanned recoverable data by file type and storage path. Find the data you want by clicking "Type" or "Path" in the left panel. Then, check the boxes in front of the data you want to recover.

Step 4. Recover and Save Data on an External Disk

Click the "Recover" button, and a pop-up window will show up saying, "Please select a target location to save". Choose the external disk as the new storage location of your recovered data.

For severe physical damage, consult a professional recovery service. You can share this recovery plan on social media to help more friends!

Conclusion

When your Mac shows "Unable to verify startup disk," it signals critical file system or hardware issues. Use Disk Utility's First Aid for repairs, and Terminal commands for advanced fixes. Persistent failures, reinstall macOS, or reset NVRAM/SMC. Always prioritize data recovery software like EaseUS Data Recovery Wizard for Mac before drastic measures. If problems persist, consult Apple Support or consider replacing the hardware.

Mac Startup Disk Cannot Be Verified FAQs

1. What to do if I accidentally delete the Mac startup disk?

If you have accidentally deleted Macintosh HD, immediately enter macOS Recovery (hold Command+R at startup), use Disk Utility to check disk integrity. If unrecoverable, reinstall macOS via Recovery Mode without losing personal files. For severe cases, use Time Machine backup restoration.

2. Why does choosing the startup disk on a Mac show empty?

This occurs if the disk is corrupted, unmounted, or lacks a valid macOS system. Reset NVRAM or check Startup Security Utility.

3. How do I fix no startup disk on the Mac?

Boot into Recovery Mode, run First Aid in Disk Utility. If failed, reinstall macOS. For persistent issues, reset NVRAM/SMC or erase/reformat the disk.