1,Ulimit
Set or get the shells resource usage limits
Ulimit [Options] [limit]
2,Option
①-A displays all current resource limits.
②-C size: SetCoreThe maximum value of the file. Unit: Blocks
③-N size specifies the maximum number of files that can be opened at the same time
④-L size: set the maximum value of the locked process in the memory. Unit: KB
⑤-M size: set the maximum value of resident memory that can be used. Unit: KB
⑥-S size: set the maximum value of the stack. Unit: Kbytes
7.-T size: SetCPUThe maximum usage time. Unit: Seconds
Bytes-V Size: sets the maximum value of virtual memory. Unit: Kbytes
3. Example
1) ulimit-s 262140 // set the maximum value of the stack to 256 m , the default value is 10 m
Pass/Etc/profileOr/. Bash_profileTo make the system remember this value.
Source/root/. bash_profile
/Etc/security/limits defines these values
2)Ulimit-u 10000 //Maximum number of processes of a user
3)Ulimit-N 4096 //Set the number of files that each process can open4096
4) it is recommended to set other settings to unlimited (Unlimited) Are:
①Data Segment Length:Ulimit-D Unlimited
②Maximum memory size:Ulimit-M Unlimited
③Stack size:Ulimit-s Unlimited
④CPU time:Ulimit-T Unlimited
⑤Virtual Memory:Ulimit-V Unlimited
⑥Core File SizeUlimit-C unlimited/size
Note:
file cat /proc/sys/kernel/core_pattern/ record the current core file location, core the current directory.
5) PassUlimitYou can restrict the resources of processes and users respectively. Many applications need to impose a general limit on the resource usage of the entire system. At this time, we need to modify/Proc.
/ProcThe directory contains many parameters in the current state of the system, such/Proc/sys/kernel/pid_max.
4,CLanguageUlimit,Get and set user limits.[5]
Reference
【1]Http://linux.die.net/man/1/ulimit
【2] More parameter descriptions
Http://linux.die.net/man/1/ulimit
Http://zhangyafeng0917.blog.163.com/blog/static/44436412201082921948750/
【3] Explains several application scenarios
Http://www.justwinit.cn/post/2650/
【4] Cited many Application Instances
Http://hi.baidu.com/fengjian1585/blog/item/b49aa7a232f1f1b9cbefd023.html
[ 5 ] http://linux.die.net/man/3/ulimit