Ubuntu /etc/security/limits.conf 不生效问题

一、问题描述

修改 /etc/security/limits.conf ，重启之后不生效

内容如下：

* soft nofile 2048576
* hard nofile 2048576
root soft nofile 2048576
root hard nofile 2048576
* soft nproc 80480
* hard nproc 80960
root soft nproc 80480
root hard nproc 80960

 

二、解决问题

根据网上资料的说法有几种

1. 修改 /etc/ssh/sshd_config

开启这2项

UsePAM yes
UseLogin yes

 

2. 以下几个文件

/etc/pam.d/login
/etc/pam.d/su
/etc/pam.d/sshd

确保开启了pam_limits.so

session    required   pam_limits.so

 

3. 重启系统

注意：修改了/etc/security/limits.conf ，必须要重启，才能生效。

 

以上几个，都测试了一下，open files没有生效！max user processes倒是生效了

root@ubuntu:~# 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) 7832
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 80480
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

 

最后终于找到原因了，是因为 内核参数没有配置

# 编辑配置文件
vi /etc/sysctl.conf
 
fs.nr_open = 10000000
 
# 重新加载
sysctl -p

 

再次重启，效果如下：

root@ubuntu:~# 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) 31392
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 2048576
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 80480
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

 

本文参考链接：

https://blog.51cto.com/jonyisme/1919075