How to Change Open Files Limit on OS X and macOS Sierra (10.8 - 10.14)

README.md

Have a look at load.sh file below, it contains all necessary commands to automate the process of changing system limits.

This guide has been tested on macOS High Sierra and Mojave. If you'd like to learn a theory, please continue reading.

How to Change Open Files Limit on OS X and macOS

This text is the section about OS X Yosemite (which also works for macOS Sierra) from https://docs.basho.com/riak/kv/2.1.4/using/performance/open-files-limit/#mac-os-x

The last time i visited this link it was dead (403), so I cloned it here from the latest snapshot in Archive.org's Wayback Machine https://web.archive.org/web/20170523131633/https://docs.basho.com/riak/kv/2.1.4/using/performance/open-files-limit/

Mac OS X

To check the current limits on your Mac OS X system, run:

launchctl limit maxfiles

The last two columns are the soft and hard limits, respectively.

Adjusting Open File Limits in Yosemite

To adjust open files limits on a system-wide basis in Mac OS X Yosemite, you must create two configuration files. The first is a property list (aka plist) file in /Library/LaunchDaemons/limit.maxfiles.plist that contains the following XML configuration:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
  <plist version="1.0">
    <dict>
      <key>Label</key>
        <string>limit.maxfiles</string>
      <key>ProgramArguments</key>
        <array>
          <string>launchctl</string>
          <string>limit</string>
          <string>maxfiles</string>
          <string>30000</string>
          <string>30000</string>
        </array>
      <key>RunAtLoad</key>
        <true/>
      <key>ServiceIPC</key>
        <false/>
    </dict>
  </plist>

This will set the open files limit to 30000. The second plist configuration file should be stored in /Library/LaunchDaemons/limit.maxproc.plist with the following contents:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple/DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
  <plist version="1.0">
    <dict>
      <key>Label</key>
        <string>limit.maxproc</string>
      <key>ProgramArguments</key>
        <array>
          <string>launchctl</string>
          <string>limit</string>
          <string>maxproc</string>
          <string>5000</string>
          <string>5000</string>
        </array>
      <key>RunAtLoad</key>
        <true />
      <key>ServiceIPC</key>
        <false />
    </dict>
  </plist>

Both plist files must be owned by root:wheel and have permissions -rw-r--r--. This permissions should be in place by default, but you can ensure that they are in place by running sudo chmod 644 . While the steps explained above will cause system-wide open file limits to be correctly set upon restart, you can apply them manually by running launchctl limit.

In addition to setting these limits at the system level, we recommend setting the at the session level as well by appending the following lines to your bashrc, bashprofile, or analogous file:

ulimit -n 200000
ulimit -u 5000

Like the plist files, your bashrc or similar file should have -rw-r--r-- permissions. At this point, you can restart your computer and enter ulimit -n into your terminal. If your system is configured correctly, you should see that maxfiles has been set to 200000.

limit.maxfiles.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
  <dict>
    <key>Label</key>
      <string>limit.maxfiles</string>
    <key>ProgramArguments</key>
      <array>
        <string>launchctl</string>
        <string>limit</string>
        <string>maxfiles</string>
        <string>30000</string>
        <string>30000</string>
      </array>
    <key>RunAtLoad</key>
      <true/>
    <key>ServiceIPC</key>
      <false/>
  </dict>
</plist>

limit.maxproc.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
  <dict>
    <key>Label</key>
      <string>limit.maxproc</string>
    <key>ProgramArguments</key>
      <array>
        <string>launchctl</string>
        <string>limit</string>
        <string>maxproc</string>
        <string>5000</string>
        <string>5000</string>
      </array>
    <key>RunAtLoad</key>
      <true/>
    <key>ServiceIPC</key>
      <false/>
  </dict>
</plist>

load.sh

#!/bin/sh

curl -O https://gist.githubusercontent.com/beefon/205099d46fd54bbf45a3ff0a6d314404/raw/4cae65e63840aaad6c13e8dd556d6b396f506677/limit.maxfiles.plist
curl -O https://gist.githubusercontent.com/beefon/205099d46fd54bbf45a3ff0a6d314404/raw/7105c50acfe6a3e0e25bbee88ef6d2e8479ce71f/limit.maxproc.plist

sudo nvram boot-args="serverperfmode=1 $(nvram boot-args 2>/dev/null | cut -f 2-)"

sudo mv limit.maxfiles.plist /Library/LaunchDaemons
sudo mv limit.maxproc.plist /Library/LaunchDaemons

sudo chown root:wheel /Library/LaunchDaemons/limit.maxfiles.plist
sudo chown root:wheel /Library/LaunchDaemons/limit.maxproc.plist

sudo launchctl load -w /Library/LaunchDaemons/limit.maxfiles.plist
sudo launchctl load -w /Library/LaunchDaemons/limit.maxproc.plist

This fork enables macOS Server Performance Mode (needs restarting) and sets maximum proc count to 5000. Useful for CI machines.