MacOS: Too Many Open Files

I ran across this error while trying to surf around the internet on my Mac today in Google Chrome. The Chrome error message was RESULT_CODE_INVALID_CMDLINE_URL.  I also noticed that my Time Machine backups were failing. This lead me on a chase to figure out why this was happening, seemingly random.

I opened the Console app on my Mac and observed many messages from apps stating “Too many open files.” I also noticed that this only seemed to happen while the system is trying to run a Time Machine backup. Any other time it seems to be fine.

My iMac is a file server and Plex media server for my entire home network. So with all of the running processes on the system, it makes sense that I am hitting some kind of limit. Turns out that there is a limit set on how many files can be open at any given time by the system, and to solve this issue, we need to increase these limits.

I stumbled across this SuperUser post on StackExchange. This is exactly what I was experiencing!

To fix this, we need to launch a terminal window and run a few commands:

sudo sysctl -w kern.maxfiles=20480
sudo sysctl -w kern.maxfilesperproc=18000

Then, to make the change permanent, we need to create a new file. Run the following command:

sudo nano /etc/sysctl.conf

Enter the following lines into the file:

kern.maxfiles=20480
kern.maxfilesperproc=18000

Press Ctrl+X and Y to save the file.

Now, your system should be functioning normally again!