Disk Utility throws the error “Invalid node structure” when I repair my external drive with First Aid. The message also says that it can’t repair the disk and I must back up its data. The irony is that this is my only backup disk with lots of data that I won’t want to lose. I can’t really access this drive, so backup is not an option. Is there any fix? Also, what causes invalid node structure on Mac, and how to repair it on Mac?
“Invalid node structure” suggests something in your drive’s filesystem is corrupted and the disk can collapse anytime. If those data is truly important, you should recover them with iBoysoft Data Recovery for Mac and then try the troubleshooting tips below.
Way 1: Use fsck to repair the invalid node structure
When Disk Utility can’t repair a drive, it’s a good practice to run the fsck command instead. Depending on your drive’s file system, the command will differ slightly.
First, open Terminal and find out the disk identifier of the volume, such as disk1s1.
Then execute the proper command to repair it with fsck: (after replacing disk1s1 with your volume identifier)
If your drive is formatted in HFS (Mac OS Extended), run:
sudo fsck_hfs -Rc /dev/disk1s1
If your drive is formatted in APFS, run:
sudo fsck_apfs -y /dev/disk1s1
Note that the sudo command will require you to enter your administrator password.
Way 2: Reformat the drive
If the error “Invalid node structure” remains when repairing your external hard drive on Mac, consider reformatting the disk.
Warning: Reformatting a drive will remove all data it contains. Make sure you’ve recovered the important data before beginning.
- Open Disk Utility.
- Click View > Show All Devices.
- Select the physical disk of the external hard drive that experiences the error “Invalid node structure” and click Erase.
- Name it.
- Choose a file system.
- Keep the scheme GUID Partition Map.
- Click Erase.