What is a partition map?
A partition map, also named as partition scheme by Apple, is used to describe how the disk is divided up. The partition map defines how exactly the data store on the disk, where each partition lies on the disk, its size and the type. Apple directly supports three partition maps: GUID (Globally Unique Identifier) Partition Table, Apple Partition Map, and Master Boot Record. It’s well known that formatting a drive with APFS requires GUID partition map.
What if APFS partition map corrupted?
Though it is an unusual occurrence, just like the other file systems, you may encounter a corrupted APFS partition map which will typically prevent you from accessing the APFS partition. Neither the APFS partition will show up in Finder nor on desktop. If you check it in Disk Utility, the APFS partition will show on the left panel. This passage will show you how to fix a broken GUID partition map on macOS Mojave/High Sierra.
How to fix corrupted APFS partition map?
The following are two effective methods to fix damaged partition map, and how to recover data after APFS partition map corrupted.
Have you backed up important data?
First of all, you should make sure you have backed up important files. Because in this situation, any operation, even disk repair, will overwrite all data stored on the APFS partition. Please stop using the APFS partition and perform data recovery as soon as possible.
iBoysoft Mac Data Recovery is highly recommended to recover lost data after APFS partition map damage. This powerful APFS data recovery tool performs well in different data loss situations, such as recovering lost data from encrypted APFS volume, recovering data from formatted APFS drive, recovering data from unmountable APFS drive, recovering data from unreadable APFS drive, recovering data from corrupted APFS drive, recovering data from inaccessible APFS drive, recovering deleted/lost APFS partition.
Tutorial to recover data after partition map damage with iBoysoft Mac Data Recovery
Step 1: Download and install iBoysoft Mac Data Recovery on Mac.
Step 2: Launch iBoysoft Mac Data Recovery.
Step 3: Select the drive whose partition map is damaged and click "Next".
Step 4: After previewing the scanning results, choose the needed files and click "Recover" to get them back.
Step 5: Have a check to ensure we have got all lost data back.
Furthermore, iBoysoft Mac Data Recovery can also recover data from Mac volumes formatted with APFS, HFS+, HFS, FAT32 and exFAT. It supports multiple file formats including documents, photos, audios, videos, emails and various storage devices like hard drive, external hard drive, USB, SD card, memory card, pen drive, etc. on macOS Mojave 10.14/High Sierra 10.13/10.12 Sierra and Mac OS X 10.11/10.10/10.9/10.8/10.7.
Fix 1: Run First Aid in Disk Utility
First Aid in Disk Utility is a handy tool to verify and repair file system errors. Although it only fixes minor disk errors, you can still have a try to repair corrupted APFS partition map.
Step 1: Launch Disk Utility.
Step 2: Choose the APFS partition on the left sidebar.
Step 3: Select First Aid in the top center and click Run.
Fix 2: Erase the APFS partition
If you have no luck to repair corrupted APFS partition map, you should erase the APFS partition to rebuilt the APFS partition map.
Step 1: Launch /Applications/Utilities/Disk Utility.app.
Step 2: Tick View widget at the top left to select "Show All Devices".
Step 3: Select your device. Then, from the tabs at the top select Erase.
Step 4: In the drop-down sheet select: volume name, "APFS” and “GUID Partition Map". Then click Erase button.
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