phMak wrote:
Here is an example with a simpler file:
$ stat -x ulysse.mp3
File: "ulysse.mp3"
Size: 3503043 FileType: Regular File
Mode: (0644/-rw-r--r--) Uid: ( 501/pn) Gid: ( 20/ staff)
Device: 1,18 Inode: 432239 Links: 1
Access: Tue Oct 21 17:02:17 2025
Modify: Mon May 12 10:11:58 2008
Change: Tue Sep 16 09:12:10 2025
Birth: Mon May 12 10:11:58 2008
$ cp ulysse.mp3 /tmp
cp: /tmp/ulysse.mp3: fcopyfile failed: No such file or directory
$ wc ulysse.mp3
wc: ulysse.mp3: read: No such file or directory
$
•
The file exists in directory structure but is unreachable, whatever the tool I use to open it.
This seems to imply the directory entry is there, but the file itself is no longer connected to that entry. You can interact with the directory entry to get basic file stats, but cannot interact with the file itself as shown by the "cp" & "wc" commands.
Then for safety, I tried fsck and I saw these alarming messages about "alloced_size". I assume there is a relation between these fsk errors and the lost files. fsck didn't repair the errors and claims everything is OK.
First Aid lies about the summary results. It is Apple brushing the problems it cannot resolve under the carpet until things break, then will have people perform a clean install of macOS & restore from a backup.
If you look at the First Aid error messages you provided originally, they line up perfectly with what you are seeing with your "stat", "cp", and "wc" tests above.
error: alloced_size (4096) of dstream (id 403216) does not match calculated size (0)
This is showing the directory thinks the file is of size 4096, but the calculated value is 0. Seems to match the finding of your experiment.
So, I wonder:
if there is a risk that these errors will spread and corrupt more files,
Possibly. We don't know what caused the problem and probably will never know.
• if I can still trust my disk,
Can you? I personally would not trust it.
• if a complete reinstall will change something,
You would need to perform a clean install which involves having that APFS Data volume reformatted (aka "erased" in Apple speak) to create a fresh clean file system. On an M-series Mac you need to follow Apple's instructions in the following Apple article:
Erase your Mac and reset it to factory settings - Apple Support
I personally would use the "Disk Utility" version section of erasing the Mac since I am not 100% certain that Step #2 "Erase All Contents & Settings" will actually reformat that Data volume (likely it will, but Apple doesn't specifically mention that tiny detail...the "erasing" of content could just be macOS deleting items).
• if I should rather change of laptop ?
Do you need a new laptop?
Until you erase the file system or perform a DFU Firmware Restore.....you have not reached that point. You just have a corrupt file system. What corrupted the file system? No idea...it happens. As long as a hardware issue is not the cause, then this laptop can still be used normally once you deal the corrupt file system.