How to change file descriptor limit settings on Mac OS

howto.md

I got a "too many open files" error.

Error: EMFILE: too many open files, open '/path/to/filename'

I solved the problem by changing the file descriptor limit setting.

Environment

• MacBook Pro 13-inch (2019)
• macOS Mojave 10.14.5

How to change

Check current settings.

$ launchctl limit
	cpu         unlimited      unlimited
	filesize    unlimited      unlimited
	data        unlimited      unlimited
	stack       8388608        67104768
	core        0              unlimited
	rss         unlimited      unlimited
	memlock     unlimited      unlimited
	maxproc     1418           2128
	maxfiles    256            unlimited

Write the following settings in /Library/LaunchDaemons/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>524288</string>
      <string>524288</string>
    </array>
    <key>RunAtLoad</key>
    <true/>
    <key>ServiceIPC</key>
    <false/>
  </dict>
</plist>

Reboot MacOS and check current settings.

$ launchctl limit
	cpu         unlimited      unlimited
	filesize    unlimited      unlimited
	data        unlimited      unlimited
	stack       8388608        67104768
	core        0              unlimited
	rss         unlimited      unlimited
	memlock     unlimited      unlimited
	maxproc     1418           2128
	maxfiles    524288         524288