After updating to macOS Catalina, all the folders I had saved in the root directory, "/", were missing.
I read that the system is now read-only, but didn't see a notice on where previous files have gone.
Are they on the system or do I need to restore them from backup?
This took me a long time to figure out, but any file that was formerly at, e.g., /my-cool-directory was moved to /Users/Shared/Relocated Items/Security/my-cool-directory.
I ended up moving the directories by running this command from the terminal:
cd "/Users/Shared/Relocated Items/Security"
sudo mv my-cool-directory ~/
# enter your system password when it asks you
After doing that, my file is then located in my home directory, e.g. ~/my-cool-directory
After a subsequent Mac OS X update, the files may be in /Users/Shared/Previously Relocated Items.
~ directory, my-cool-directory can also be moved to /private. It will sit there more prominently than in the home directory.
– oliolioli
Oct 13 '20 at 09:50
You can use the file /etc/synthetic.conf to map your old folder to a new virtual folder on the root directory. If the file doesn't exists, just create it with sudo :
sudo nano /etc/synthetic.conf
Add the folder you want to use in the root directory, and the directory you want to mount on.
Ex:
my-cool-directory /Users/Shared/Relocated Items/Security/my-cool-directory
Finish by rebooting your mac.
PS: Be careful with your synthetic.conf file. A colleague emailed the content of his file and it had a space between the virtual name and the path. Your system will simply power-off about 15 seconds into the boot process.
You must have only one tab character only between my-cool-directory and /Users/Shared/Relocated Items/Security/my-cool-directory.
You can find more infos with man synthetic.conf
