The root user runs the following
ulimit -a | grep open
and gets a result of
open files (-n) 65536
A user runs the same command and gets a result of
open files (-n) 65000
How can you set the ulimit of the user to 8162?
You can just run ulimit -n to reduce the limit:
$ ulimit -n 8192
$ ulimit -n
8192
However, the user can override this limit. If you want to establish a hard limit for this user, you need to edit the file /etc/security/limits.conf.
I have changed /etc/security/limits.com and rebooted the machine remotely, However, after the boot, the nproc parameter has still the old value.
[ost#compute-0-1 ~]$ cat /etc/security/limits.conf
* - memlock -1
* - stack -1
* - nofile 4096
* - nproc 4096 <=====================================
[ost#compute-0-1 ~]$
Broadcast message from root#compute-0-1.local
(/dev/pts/0) at 19:27 ...
The system is going down for reboot NOW!
Connection to compute-0-1 closed by remote host.
Connection to compute-0-1 closed.
ost#cluster:~$ ssh compute-0-1
Warning: untrusted X11 forwarding setup failed: xauth key data not generated
Last login: Tue Sep 27 19:25:25 2016 from cluster.local
Rocks Compute Node
Rocks 6.1 (Emerald Boa)
Profile built 19:00 23-Aug-2016
Kickstarted 19:08 23-Aug-2016
[ost#compute-0-1 ~]$ ulimit -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 516294
max locked memory (kbytes, -l) unlimited
max memory size (kbytes, -m) unlimited
open files (-n) 4096
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 0
stack size (kbytes, -s) unlimited
cpu time (seconds, -t) unlimited
max user processes (-u) 1024 <=========================
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited
Please see that I set max user processes to 4096 but after the reboot, the value is still 1024.
Please take a look at a file named /etc/pam.d/sshd .
If you can find it, open the file and insert a following line.
session required pam_limits.so
Then the new value will be effective even after rebooting.
PAM is a module which is related to authentication. So you need to enable the module through ssh login.
More details on man pam_limits.
Thanks!
Is there a way to increase the ulimit -n (open files) for an Amazon EC2 instance? I am running an amazon m3.2xlarge ubuntu instance for testing purposes. The ulimit -Hn is 4096 but I need over 10k. I have even tried temporarily getting higher instance types but no luck.
I have googled around for quite a while but there are only topics on this that are a few years old. Most suggest changing the limits.conf file found in /etc/security/limits.conf but the limit is read only so I cannot change permissions.
Are there any alternative ways to change this ?
Edit - my etc/security/limits.conf file
#* soft core 0
#root hard core 100000
root soft nofile 16500
root hard nofile 16500
#* hard rss 10000
##student hard nproc 20
##faculty soft nproc 20
##faculty hard nproc 50
#ftp hard nproc 0
#ftp - chroot /ftp
##student - maxlogins 4
I ran into this issue recently and resulted in editing /etc/security/limits.conf in my UserData script. It ended up looking something like this:
#!/bin/bash
echo "* hard nofile 65535" | tee --append /etc/security/limits.conf
echo "* soft nofile 65535" | tee --append /etc/security/limits.conf
Note that the 'user' for the limits.conf is *, meaning all users will have 65535 as their limit.
If you set up the instance or you have sudo privileges, you can change those configuration files. Just prepend your command to open the file with sudo, (example sudo vi /etc/security/limits.conf).
I have a server with Debian wheezy x64, I have problem with asterisk server "Try increasing max file descriptors with ulimit -n", I try to change the file descriptor limit as follows:
# su - asterisk
$ ulimit -Hn
4096
$ ulimit -Sn
1024
$ exit
# vi /etc/security/limits.conf
I added in the end of the file:
....
asterisk soft nofile 65535
asterisk hard nofile 65535
# End of file
And when I try to test:
# su - asterisk
$ ulimit -Hn
4096
$ ulimit -Sn
1024
$
am I miss somethings? (I rebooted the server but I get the same values)
I used this tutorial
I found a solution, just I change the configuration in the file /etc/security/limits.conf with following lines:
....
* soft nofile 65535
* hard nofile 65535
# End of file
Currently ulimit -n shows 10000. I want to increase it to 40000. I've edited "/etc/sysctl.conf" and put fs.file-max=40000. I've also edited /etc/security/limits.conf and updated hard and soft values. But still ulimit shows 10000. After making all these changes I rebooted my laptop. I've access to root password.
usr_name#usr_name-lap:/etc$ /sbin/sysctl fs.file-max
fs.file-max = 500000
Added following lines in /etc/security/limits.conf -
* soft nofile 40000
* hard nofile 40000
I also added following line in /etc/pam.d/su-
session required pam_limits.so
I've tried every possible way as given on other forums, but I can reach up to a maximum limit of 10000, not beyond that. What can be the issue?
I'm making this change because neo4j throws maximum open file limits reached error.
What you are doing will not work for root user. Maybe you are running your services as root and hence you don't get to see the change.
To increase the ulimit for root user you should replace the * by root. * does not apply for root user. Rest is the same as you did. I will re-quote it here.
Add the following lines to the file: /etc/security/limits.conf
root soft nofile 40000
root hard nofile 40000
And then add following line in the file: /etc/pam.d/common-session
session required pam_limits.so
This will update the ulimit for root user. As mentioned in comments, you may don't even have to reboot to see the change.
1) Check sysctl file-max limit:
$ cat /proc/sys/fs/file-max
If the limit is lower than your desired value, open the sysctl.conf and add this line at the end of file:
fs.file-max = 65536
Finally, apply sysctl limits:
$ sysctl -p
2) Edit /etc/security/limits.conf and add below the mentioned
* soft nproc 65535
* hard nproc 65535
* soft nofile 65535
* hard nofile 65535
These limits won't apply for root user, if you want to change root limits you have to do that explicitly:
root soft nofile 65535
root hard nofile 65535
...
3) Reboot system or add following line to the end of /etc/pam.d/common-session:
session required pam_limits.so
Logout and login again.
4) Check soft limits:
$ ulimit -a
and hard limits:
$ ulimit -Ha
....
open files (-n) 65535
Reference : http://ithubinfo.blogspot.in/2013/07/how-to-increase-ulimit-open-file-and.html
I am using Debian but this solution should work fine with Ubuntu.
You have to add a line in the neo4j-service script.
Here is what I have done :
nano /etc/init.d/neo4j-serviceAdd « ulimit –n 40000 » just before the start-stop-daemon line in the do_start section
Note that I am using version 2.0 Enterprise edition.
Hope this will help you.
I was having the same issue, and got it to work by adding entries to /etc/security/limits.d/90-somefile.conf. Note that in order to see the limits working, I had to log out completely from the ssh session, and then log back in.
I wanted to set the limit for a specific user that runs a service, but it seems that I was getting the limit that was set for the user I was logging in as. Here's an example to show how the ulimit is set based on authenticated user, and not the effective user:
$ sudo cat /etc/security/limits.d/90-nofiles.conf
loginuser soft nofile 10240
loginuser hard nofile 10240
root soft nofile 10241
root hard nofile 10241
serviceuser soft nofile 10242
serviceuser hard nofile 10242
$ whoami
loginuser
$ ulimit -n
10240
$ sudo -i
# ulimit -n
10240 # loginuser's limit
# su - serviceuser
$ ulimit -n
10240 # still loginuser's limit.
You can use an * to specify an increase for all users. If I restart the service as the user I logged in, and add ulimit -n to the init script, I see that the initial login user's limits are in place. I have not had a chance to verify which user's limits are used during a system boot or of determining what the actual nofile limit is of the service I am running (which is started with start-stop-daemon).
There's 2 approaches that are working for now:
add a ulimit adjustment to the init script, just before start-stop-daemon.
wildcard or more extensive ulimit settings in the security file.
You could alter the init script for neo4j to do a ulimit -n 40000 before running neo4j.
However, I can't help but feel you are barking up the wrong tree. Does neo4j legitimately need more than 10,000 open file descriptors? This sounds very much like a bug in neo4j or the way you are using it. I would try to address that.
I have lots of trouble getting this to work.
Using the following allows you to update it regardless of your user permission.
sudo sysctl -w fs.inotify.max_user_watches=100000
Edit
Just saw this from another user also on another stackexchange site (both work, but this version permanently updates the system setting, rather than temporarily):
echo fs.inotify.max_user_watches=100000 | sudo tee -a /etc/sysctl.conf;
sudo sysctl -p
Try run this command it will create a *_limits.conf file under /etc/security/limits.d
echo "* soft nofile 102400" > /etc/security/limits.d/*_limits.conf && echo "* hard nofile 102400" >> /etc/security/limits.d/*_limits.conf
Just exit from terminal and login again and verify by ulimit -n it will set for * users
tl;dr set both the soft and hard limits
I'm sure it's working as intended but I'll add it here just in case.
For completeness the limit is set here (see below for syntax):
/etc/security/limits.conf
some_user soft nofile 60000
some_user hard nofile 60000
and activated with the following in /etc/pam.d/common-session:
session required pam_limits.so
If you set only the hard limit, ulimit -a will show the default (1024):
If you set only the soft the limit ulimit -a will show (4096)
If you set them both ulimit -a will show the soft limit (up to the hard limit of course)
I did it like this
echo "NEO4J_ULIMIT_NOFILE=50000" >> neo4j
mv neo4j /etc/default/
ULIMIT configuration:
Login by root
vi security/limits.conf
Make Below entry
Ulimit configuration start for website user
website soft nofile 8192
website hard nofile 8192
website soft nproc 4096
website hard nproc 8192
website soft core unlimited
website hard core unlimited
Make Below entry for ALL USER
Ulimit configuration for every user
* soft nofile 8192
* hard nofile 8192
* soft nproc 4096
* hard nproc 8192
* soft core unlimited
* hard core unlimited
After modifying the file, user need to logoff and login again to see the new values.