How To Fix Read-Only File System Error When Run Mkdir Command On MacOS

When I run command mkdir in mac os to create a folder, it gives me an error message mkdir: /data: Read-only file system like below. This article will tell you how to fix it.

sh-3.2# mkdir /data
mkdir: /data: Read-only file system

1. Fix MacOS Read-Only File System Error Steps.

1. Restart macOS, press Command+R to go to macOS utilities window.
2. Click menu item Utilities —> Terminal at top menu bar.
3. Then input command csrutil disable in the popup terminal window. This command will disable the System Integrity Protection.
4. Click Mac Logo —> Restart menu item at the top left corner to restart the macOS.
5.  After restart macOS, run the command sudo mount -uw /.

   $ sudo mount -uw /
   Password:

6. Now you can create a directory successfully with the command mkdir.
7. If you want to check whether System Integrity Protection is enabled or disabled, you can run command csrutil status in a terminal.

   # csrutil status
   System Integrity Protection status: disabled.

8. If you want to enable System Integrity Protection, you can restart the macOS and press Command + R to go to the macOS utilities window again to enable it with command csrutil enable in terminal.

2. Resolve Read-only File System Error When Remove Files.

Now we can create a directory in the macOS system. But when I want to remove files, it also shows me below error messages.

# rm -rf /data/db
rm: /data/db/journal/WiredTigerPreplog.0000000002: Read-only file system
rm: /data/db/journal/WiredTigerLog.0000000001: Read-only file system
rm: /data/db/journal/WiredTigerPreplog.0000000001: Read-only file system

To fix this issue, you should run command sudo mount -uw /, after that, you can remove files as you want.

$ sudo mount -uw /
Password:

3. Question & Answer.

3.1 Python script meets read-only file system error on macOS.

1. In my python script, I want to use the python os module’s system function to execute a zip command to make a zip file like below.

   os.system('zip target-file.zip /usr/local/abc.py')

   But when I run the python script, it shows a permission denied error like below.

   >>> import os
   >>>
   >>> os.getcwd()
   '/usr/local'
   >>>
   >>> os.system('zip target-file.zip /usr/local/abc.py')
   zip I/O error: Permission denied
   zip error: Could not create output file (target-file.zip)
   3840

   I have run the command csrutil disable to disable the System Integrity Protection on my macOS, but it still throws the error when I run the python script.

2. You can try the below steps.1. Run the command fsck -n -f in a macOS terminal. 2. Reboot your macOS. 3. Run the python script file with the root permission.