command linemacosmojave
Running Mojave 10.14.3 I notice there are currently more files open than the maxfiles allowed. How is this possible? In this case I do not have any symptoms or error messages, but in the past I have seen an error message about too many open files, and that time when I checked, lsof was exactly 10000.
Side node: Is there any harm in increasing maxfiles?
$ sysctl kern.maxfiles
kern.maxfiles: 10000
$ lsof | wc
13242 124035 1982117
As my experience, from Mac OS X 10.7(Lion) to 10.11.5（EI Capitan), the lsof always hang.
To solve to problem, append -n option.
lsof -n
According to manual of lsof, the -n option:
inhibits the conversion of network numbers to host names for network files.
Inhibiting conversion may make lsof run faster. It is also useful when host
name lookup is not working properly
EDIT 2018-04-25: If it is still slow, you can try
-O to bypass the strategy it uses to avoid being blocked by some kernel operations
-P to inhibits the conversion of port numbers to port names for network files
-l to inhibits the conversion of user ID numbers to login names
The ultimate way to find out why so slow is to run "Instruments" tool (from upper right corner Spotlight Search icon) to do a "System Trace" on /usr/sbin/lsof then see graph and sys calls.
Though not directly answering your question you will find two solutions at superuser:
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>65536</string>
<string>65536</string>
</array>
<key>RunAtLoad</key>
<true/>
<key>ServiceIPC</key>
<false/>
</dict>
</plist>
This will set the open files limit to 65536. 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>2048</string>
<string>2048</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 <filename>. 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 65536
ulimit -u 2048
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 65536.
Adjust the maxfiles & maxproc limit as you need it
Sourced from: http://docs.basho.com/riak/latest/ops/tuning/open-files-limit/
Modifying the /etc/launchd.conf per a lot of google queries and SO suggestions didn't seem to work for me in Yosemite (10.10). What did end up working, after numerous change/reboot/test combinations, was modifying (or creating if it doesn't exist) the /etc/sysctl.conf file.
This is what I had to put in to make it work
kern.maxfiles=65536
kern.maxfilesperproc=65536
I'm not sure if 'kern.maxfiles' needs to be in there, but when I had it in there by itself I still had the same issue, when I added the 'kern.maxfilesperproc' everything started working.
If one or both of those solutions work for you, please credit the original posters.
Best Answer
lsoflists more than just file handles. Most notably, it includes program text mapped into all processes (e.g, the executable and all libraries it's using). There are a lot of these mappings in most GUI processes -- I count over 270 for the Finder, for instance -- and they don't consume file handles.If you believe you are hitting the system's open file limit, go ahead and change
kern.maxfile. However, it's more likely that you're hitting the per-process open file limit, which defaults to a lower number (7168 on my system) and can be changed usingulimit.