# mongo
MongoDB shell version: 3.0.2
connecting to: test
Server has startup warnings:
2015-05-09T12:34:19.688-0700 I CONTROL [initandlisten]
2015-05-09T12:34:19.688-0700 I CONTROL [initandlisten] ** WARNING: soft rlimits too low. rlimits set to 1024 processes, 64000 files. Number of processes should be at least 32000 : 0.5 times number of files.
>
mongodb当前限制：1024 processes, 64000 files
mongodb建议要求：processes = 0.5*files=32000（至少）
所以需要将 processes 从1024 改为 32000 或更大.
查看当前mongodb进程信息：
[root@localhost ~]# ps -ef | grep mongod
- mongod 24283 1 0 12:35 ? 00:00:04 /usr/bin/mongod -f /etc/mongod.conf
- root 24240 22049 0 12:45 pts/2 00:00:00 grep mongod
[root@localhost ~]# cat /proc/24283/limits
#可以看到限制：Max processes，Max open files
- Limit Soft Limit Hard Limit Units
- Max cpu time unlimited unlimited seconds
- Max file size unlimited unlimited bytes
- Max data size unlimited unlimited bytes
- Max stack size 10485760 unlimited bytes
- Max core file size 0 unlimited bytes
- Max resident set unlimited unlimited bytes
- Max processes 1024 32000 processes
- Max open files 64000 64000 files
- Max locked memory 65536 65536 bytes
- Max address space unlimited unlimited bytes
- Max file locks unlimited unlimited locks
- Max pending signals 14833 14833 signals
- Max msgqueue size 819200 819200 bytes
- Max nice priority 0 0
- Max realtime priority 0 0
- Max realtime timeout unlimited unlimited us
修改 Max processes 或者 files ，有几种方法：
方法一：
修改配置文件 /etc/security/limits.d/90-nproc.conf
[root@localhost ~]# vi /etc/security/limits.d/90-nproc.conf
- * soft nproc 1024
- 改为:
- * soft nproc 32000
重启 mongod 服务：
[root@localhost ~]# service mongod restart
方法二：
修改配置文件 /etc/security/limits.conf，添加配置信息：
[root@localhost ~]# vi /etc/security/limits.conf
- mongod soft nofile 64000
- mongod hard nofile 64000
- mongod soft nproc 32000
- mongod hard nproc 32000
重启 mongod 服务：
[root@localhost ~]# service mongod restart
也可以查看 limits.conf 更多配置信息和使用方法：
[root@localhost ~]# man limits.conf
查看系统限制：
[root@localhost ~]# 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) 14833
- 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) 10240
- cpu time (seconds, -t) unlimited
- max user processes (-u) 14833
- virtual memory (kbytes, -v) unlimited
- file locks (-x) unlimited
mongodb推荐设置：
- -f (file size): unlimited
- -t (cpu time): unlimited
- -v (virtual memory): unlimited
- -n (open files): 64000
- -m (memory size): unlimited
- -u (processes/threads): 64000
直接在当前shell中设置：ulimit -n <value>
- ulimit -f unlimited
- ulimit -t unlimited
- ulimit -v unlimited
- ulimit -n 64000
- ulimit -m unlimited
- ulimit -u 64000
若要系统启动时在所有生效，将上面的 ulimit 添加到 /etc/profile
[root@localhost ~]# vi /etc/profile
mongodb shell警告
原文：http://www.cnblogs.com/chenweixuan/p/5191826.html
