zoukankan      html  css  js  c++  java
  • Linux Increase The Maximum Number Of Open Files / File Descriptors (FD)

    How do I increase the maximum number of open files under CentOS Linux? How do I open more file descriptors under Linux?



    The ulimit command provides control over the resources available to the shell and/or to processes started by it, on systems that allow such control. The maximum number of open file descriptors displayed with following command (login as the root user).

    Command To List Number Of Open File Descriptors

    Use the following command command to display maximum number of open file descriptors:
    cat /proc/sys/fs/file-max
    Output:

    75000

    75000 files normal user can have open in single login session. To see the hard and soft values, issue the command as follows:
    # ulimit -Hn
    # ulimit -Sn

    To see the hard and soft values for httpd or oracle user, issue the command as follows:
    # su - username
    In this example, su to oracle user, enter:
    # su - oracle
    $ ulimit -Hn
    $ ulimit -Sn

    System-wide File Descriptors (FD) Limits

    The number of concurrently open file descriptors throughout the system can be changed via /etc/sysctl.conf file under Linux operating systems.

    The Number Of Maximum Files Was Reached, How Do I Fix This Problem?

    Many application such as Oracle database or Apache web server needs this range quite higher. So you can increase the maximum number of open files by setting a new value in kernel variable /proc/sys/fs/file-max as follows (login as the root):
    # sysctl -w fs.file-max=100000
    Above command forces the limit to 100000 files. You need to edit /etc/sysctl.conf file and put following line so that after reboot the setting will remain as it is:
    # vi /etc/sysctl.conf
    Append a config directive as follows:
    fs.file-max = 100000
    Save and close the file. Users need to log out and log back in again to changes take effect or just type the following command:
    # sysctl -p
    Verify your settings with command:
    # cat /proc/sys/fs/file-max
    OR
    # sysctl fs.file-max

    User Level FD Limits

    The above procedure sets system-wide file descriptors (FD) limits. However, you can limit httpd (or any other users) user to specific limits by editing /etc/security/limits.conf file, enter:
    # vi /etc/security/limits.conf
    Set httpd user soft and hard limits as follows:
    httpd soft nofile 4096
    httpd hard nofile 10240

    Save and close the file. To see limits, enter:
    # su - httpd
    $ ulimit -Hn
    $ ulimit -Sn

    A note about RHEL/CentOS/Fedora/Scientific Linux users

    Edit /etc/pam.d/login file and add/modify the following line (make sure you get pam_limts.so):

    session required pam_limits.so

    Save and close the file.

    FROM:https://www.cyberciti.biz/faq/linux-increase-the-maximum-number-of-open-files/

  • 相关阅读:
    在 Java SE 6 中监视和诊断性能问题
    Codeforces Round #491 (Div. 2)部分题解
    BZOJ1607: [Usaco2008 Dec]Patting Heads 轻拍牛头(模拟 调和级数)
    BZOj1261: [SCOI2006]zh_tree(dp)
    BZOJ1569: [JSOI2008]Blue Mary的职员分配(dp 暴力)
    BZOJ4300: 绝世好题(dp)
    树上莫队算法
    SPOJ COT2
    BZOJ1086: [SCOI2005]王室联邦(贪心,分块?)
    Educational Codeforces Round 42 (Rated for Div. 2)
  • 原文地址:https://www.cnblogs.com/rusking/p/6101723.html
Copyright © 2011-2022 走看看