Macbook Air doesn't want to run in any way. It happened after I (I do not understand why) changed the access rights to all files and folders on the disk to read-only for the user system and for the pair of groups "wheel" and "stuff". Changed not through the terminal, but in the folder properties window of the OS X drive.

The rights for my account (mac01), under which I work, were and remained full to all files on the disk.

As a solution, I launched the Mac in Single-User mode and entered the following commands:

fsck -f mount -uw / chmod -R ugo+rwx /

Check disk did not give any errors. Then everything went well without errors.

But this did not help, as well as numerous tips from the network (safe mode, booting with system diagnostics, etc.). Checking the disk, fixing access rights by the utility from recovery mode also did not lead to the result. The download still hangs around 55% (on the screen with the Apple logo and progress bar).

If anyone came across this, then I beg you to help. The service (unofficial) said that there may be a problem with the hard drive and will have to change it. In general, they could not help.

But, since the problem started after I had something to do with access rights, it makes me think that it’s all about the software and not about the hardware. The data that is stored on the disk is very important. I know how to transfer them to an external drive, but I would not like to install the system from scratch and then copy everything back. Therefore, looking for the option of correcting the mistakes made.

    1 answer 1

    I will duplicate my answer given about another, but also unix-like system (in this respect, the answer is quite universal):

    From my point of view, the most effective way out of this situation is to save data files and reinstall the system.

    the fact that the system does not load in the “normal” mode is only the very tip of the “iceberg”, the other consequences will be revealed later, at the most probably unexpected moments. of the main “results”, we can mention at least a couple: first, your system is now a “leaky sieve” (in terms of system security and security), secondly, some “demons” can either stop working altogether (after rebooting ), or work incorrectly.

    I personally (considering myself far from being a novice) would not even undertake to correct the consequences of such “vandalism” - this is hellish hard work.