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Unable to fork error for execRSS

3 replies

Last post Aug 28, 2018 08:28 PM by williamyiu

  • Unable to fork error for exec

    Sep 08, 2014 10:18 AM|thepdcemulator|LINK

    We are running PHP 5.5.9 (NTS, x86) on Windows Server 2012 R2 with FCGI, Kerberos Auth and fastcgi.impersonate = 1. Application Pool runs with a AD User Service Account, W3P Service runs with "local system" Account.

    Execution is enabled in IIS Script Handler for FCGI-PHP. Handler Feature Permissions is also set to "Execute".

    Now I am trying to run a application from command line, but this also simple commands like dir or ping are failing with "unable to fork".


    Warning: exec(): Unable to fork [dir] in D:\mypath\myfile.php on line 2

    I have tried in my DEV-Environment:
    - added read+execute Permissions to "Everyone" to c:\windows\syswow64\cmd.exe
    - copied c:\windows\syswow64\cmd.exe to PHP-dir
    - added read+execute Permissions to ISUSR to cmd.exe im PHP-dir
    - added read+execute Permissions to IIS_IUSRS to cmd.exe im PHP-dir
    - upgraded to PHP 5.5.16
    - watched with sysinternals procmon, found no error or something
    - searched hours and hours for this on the web

    Any hints? Thank you for your help!

  • Re: Unable to fork error for exec

    Aug 25, 2016 10:39 PM|cstobbe|LINK

    I had this problem. It was caused by conflicting IIS settings in these 2 locations:

    • Application Pool > Advanced Settings > Process Model > Identity
      This was set to a domain user. This was the correct setting for how we needed to run our web site.
    • Web site > Authentication > Anonymous Authentication
      This was set to the same "Specific user" as the application pool. It should have been set to "Application Pool Identity".

    After I changed the web site authentication to "Application Pool Identity", exec() ran successfully.

  • Re: Unable to fork error for exec

    Nov 19, 2017 07:26 AM|iisdev2001|LINK

    Finally! That's it! Thank you.

  • Re: Unable to fork error for exec

    Aug 28, 2018 08:28 PM|williamyiu|LINK

    I tried this and it solved the "Unable to fork" issue. But the site can't create symlink. Any help?