On my 2014 15-inch MacBook Pro (macOS Sierra), I ran First Aid in Disk Utility and received exit code 8, indicating that the disk needs repair and suggesting to retry in Recovery Mode. After running First Aid in Recovery Mode, it showed exit code 0 (everything is fine). However, when I reran First Aid in Normal Mode, I still received the same error with exit code 8. Do you know how I can fix this?
You can try forcing a disk repair. First, enter Recovery Mode:
Intel Mac: Restart your Mac and hold down Command + R until you see the Apple logo or a loading bar.
Apple Silicon (M1/M2/M3) Mac: Shut down your Mac, then press and hold the Power button until “Loading startup options” appears. Select macOS Utilities.
Once in Recovery Mode, open Disk Utility and locate your disk in the left-hand list. If the disk appears as “Not Mounted,” click Mount first. Then, click First Aid and run the disk repair. After the repair is complete, restart your Mac and check if the issue is resolved.
Read this article to find more solutions: Fix File System Check Exit Code Is 8 on Mac
If your file system is corrupted, the fastest solution is to recover the data from your disk first and then format the disk. To retrieve data from a damaged file system, professional data recovery software is necessary. You can try iBoysoft Data Recovery for Mac, which has a high recovery rate. I previously used it to successfully recover data from a damaged disk. Download iBoysoft Data Recovery for Mac
Once the data recovery is complete, open Disk Utility, select your disk, and click Erase. Then, choose the appropriate format based on your macOS version: APFS (for macOS 10.13 and later) or Mac OS Extended (Journaled) (for macOS 10.12 and earlier). After formatting, your disk should be ready for use again.