exceeds the maximum size of ast_fdset error on Asterisk-1.8.0

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Asterisk Users 8 Comments

Hi Friends,

i have installed and configure asterisk-1.8.0.
When i have tried asterisk start get below errors and not able to start

*FD 32767 exceeds the maximum size of ast_fdset!*

Thanks in advance.

8 thoughts on - exceeds the maximum size of ast_fdset error on Asterisk-1.8.0

  • At startup, this message is innocuous. Unfortunately, I cannot disable
    this message at startup, or it will invalidate future checking (when it
    REALLY matters). Out of curiosity, what platform are you running on? On
    most platforms that are able to run Asterisk, with the possible exception
    of Solaris, increasing the maximum file descriptor for use with select(2) is

  • Sorry for resurrecting an old thread…

    Tilghman Lesher writes:

    I am not entirely sure yet, but it looks like Asterisk 1.8.x fails to
    increase the maximum file descriptor when running on Linux, if configure
    is not run as root.

    If configure is run as root, everything works as expected.


  • Correct; and Asterisk needs to be started as root, even if it will drop
    privileges after startup. Do this, and there should be no problems.

  • Benny Amorsen wrote:

    Not so, I always run ./configure as root and I get the message that
    32768 exceeds …

  • And what platform are you running on? Are you perhaps running on an
    SELinux platform, where root isn’t really root? Or are you running on
    something that isn’t Linux and never bothered to allow a single process
    to readily handle more than 1024 file descriptors at once? I need an answer
    if we’re going to ever solve this issue, not just whining about how it
    doesn’t work.

  • Tilghman Lesher writes:

    Starting as root + dropping privileges is fine. Running configure as
    root is not so fine; that basically makes building RPMS impossible.


  • Alternatively, if you can set “ulimit -n 32768” in your RPM build
    environment (this needs to be set as a login requirement), you can sidestep
    the need for configure to run as root. The only reason it needs root is to
    expand the file descriptor limit so it can test using a file descriptor
    beyond 1023 (the usual limit).

  • Hi Friends,

    I have occurred same problem on Asterisk-1.8.X. version.
    I need to upgrade our production asterisk- server to asterisk-1.8.X
    I have already used “root” user during configuration and installation of
    asterisk-1.8.X version but getting same error as “*increase the maximum file
    descriptor*” on centos-5.3 os.

    I have also set 32768 ulimit of file descriptor on centos but still no

    Thanks in advance.

    Best Regards,

    Rajnikant Vanza
    Software Engineer