查看和修改系统最大文件描述符

1.查看系统最大文件描述符

1).通过ulimit –n命令打印目前系统支持的最大文件描述符

1024

2).查看文件

cat /proc/sys/fs/file-max

2.修改系统最大文件描述符

1).使用ulimit –n 最大数  命令修改当前会话系统支持的最大文件描述符.

2).修改/etc/security/limits.conf中整个系统的最大文件描述符，不过要重启。

3.文件内容

该文件不仅仅能修改最大文件描述符,还能修改其它一些内容.

debian:/home/zhangp# cat /etc/security/limits.conf

# /etc/security/limits.conf

#

#Each line describes a limit for a user in the form:

#

#<domain>        <type>  <item>  <value>

#

#Where:

#<domain> can be:

#        - an user name

#        - a group name, with @group syntax

#        - the wildcard *, for default entry

#        - the wildcard %, can be also used with %group syntax,

#                 for maxlogin limit

#

#<type> can have the two values:

#        - "soft" for enforcing the soft limits

#        - "hard" for enforcing hard limits

#

#<item> can be one of the following:

#        - core - limits the core file size (KB)

#        - data - max data size (KB)

#        - fsize - maximum filesize (KB)

#        - memlock - max locked-in-memory address space (KB)

#        - nofile - max number of open files

#        - rss - max resident set size (KB)

#        - stack - max stack size (KB)

#        - cpu - max CPU time (MIN)

#        - nproc - max number of processes

#        - as - address space limit (KB)

#        - maxlogins - max number of logins for this user

#        - maxsyslogins - max number of logins on the system

#        - priority - the priority to run user process with

#        - locks - max number of file locks the user can hold

#        - sigpending - max number of pending signals

#        - msgqueue - max memory used by POSIX message queues (bytes)

#        - nice - max nice priority allowed to raise to values: [-20, 19]

#        - rtprio - max realtime priority

#        - chroot - change root to directory (Debian-specific)

#

#<domain>      <type>  <item>         <value>

#

 

#*               soft    core            0

#*               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

 

# End of file