786 000 Files Limit CentOS 7 – Asterisk Keep Complaining

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Hi Tony

Thanks for replying.

I suspected something like that, though repeatedly running

lsof | wc -l

Always stays quite low – 100 000 open files, which is still 8 times less than the system maximum as confirmed by running ulimit -n

I also note that this number will increase to about 125 000 but never go higher than that, then, as calls hang up, decreate again – during times when the CLI is spammed with 100s of “broken pipe” errors due to insuffiecient file descriptors, this number never reaches beyond 125 000 out of the available 800 000 open files.

If I grep by asterisk on the output of lsof the few thousand lines I have looked at all seem to indicate legitimate uses – there are at least two files for each conversation in progress (I assume for inward and outward RTP) plus one for each file being mixmonitored (which also seems logical)
and also number-of-active-calls connections to res_timing_dahdi – which all looks correct…

Ok, I will have to consider that. The thing is the problem is not consistent
– I can (for example) run 60 calls, with no problems and no reported failures in opening files, then calls will -decrease- to about 40 and then later spike to 70, but around 50 calls I get the errors coming up thousands of times in the CLI, then suddenly stop as the calls -increase- which doesn’t make sense. But this kind of behaviour does seem consistent with a possible leak.


I have now ran

/usr/bin/prlimit –pid `pidof asterisk`

and I have noticed that even though I have 800 000 files specified, the ACTUAL limit in place on Asterisk for numbers of files is only 1024?!

# prlimit –pid `pidof asterisk`
AS address space limit unlimited unlimited bytes CORE max core file size unlimited unlimited blocks CPU CPU time unlimited unlimited seconds DATA max data size unlimited unlimited bytes FSIZE max file size unlimited unlimited blocks LOCKS max number of file locks held unlimited unlimited MEMLOCK max locked-in-memory address space 65536 65536 bytes MSGQUEUE max bytes in POSIX mqueues 819200 819200 bytes NICE max nice prio allowed to raise 0 0
NOFILE max number of open files 1024 4096
NPROC max number of processes 30861 30861
RSS max resident set size unlimited unlimited pages RTPRIO max real-time priority 0 0
RTTIME timeout for real-time tasks unlimited unlimited microsecs SIGPENDING max number of pending signals 30861 30861
STACK max stack size 8388608 unlimited bytes

Accordingly I have put this into a cronjob ran each minute:

prlimit –pid `pidof asterisk` –nofilex6000:786000

to try and force the running binary to keep a high file limit (sources say to keep it less than the ACTUAL system file limit, in my case 800 000 files)
on the live Asterisk process.

I’ll see if this maybe helps – the above runs via cron each minute.

So it appears for some reason somehow the live running asterisk process
“loses track” of how many open files it may have, or when it starts it somehow does not start with the correct number of maximum open files, as set in the system / kernel config?

Anyway, thank you for replying, I’ll monitor this new “Cronjob fixup” I’m trying and see if it helps.

No wonder it is complaining about running out of file handles if it ACTUALLY
was only using 1024!

Kind regards


5 thoughts on - 786 000 Files Limit CentOS 7 – Asterisk Keep Complaining

  • Hi Stefan,

    we ran into a similar problem using Debian.

    There we are able to check the current limits using:

    pidof asterisk -> 23351
    cat /proc/23351/limits

    Limit Soft Limit Hard Limit Units Max open files 1024 1024 files

    I think that in the end


    * hard nofile 500000
    * soft nofile 500000
    root hard nofile 500000
    root soft nofile 500000

    did the trick. We also tried

    vi /etc/sysctl.conf fs.file-max = 500000

    not sure what the solution in the end was. But I remember rebooting was important.


    Am 11.08.2015 um 11:00 schrieb Stefan Viljoen:

  • In article <002b01d0d414$36af31b0$a40d9510$@verishare.co.za>, Stefan Viljoen wrote:

    From what you said below, the above is probably not relevant…

    Yes, this is likely. Have a look in /usr/sbin/safe_asterisk, at the commented-out settings for SYSMAXFILES and MAXFILES, and try setting those.

    Cheers Tony

  • What the ‘h’ are you doing that takes x00,000 open files?

    I’m running Asterisk 11.17.0 on CentOS 6.7 and my ‘numbers’ seem insignificant by comparison.

    sudo /usr/sbin/asterisk -r -x ‘core show channels’ | grep active
    347 active channels
    344 active calls

    sudo lsof | wc -l

    sudo lsof | grep asterisk | wc -l

  • Hi Steve

    Just running about 50 calls??

    If I do

    lsof | grep asterisk | wc -l

    to narrow the realm of what is reported I still get just under 100 000

    lsof | grep asterisk | wc -l

    with 50 calls running.

    So apparently this is excessive? I can only guess that there must be a MAJOR
    bug in given that you are running 347 calls on 2161 open files with Ast 11…?

    I’m on CentOS 7.

    As I mentioned previously, I have found that my problem with Asterisk running out of files is that the Asterisk binary, on startup, does NOT
    “detect” that the open file limit it 768 000, it always selects 1024 as the soft limit for open files and 4096 as the hard limit for open files. I have to manually (cron does not work – wonder why?) do

    /usr/bin/prlimit –pid `pidof asterisk` –nofilex6000:786000

    in order to get the running Asterisk instance to ACTUALLY have a soft and hard number of files limit of 786 000.

    The machine under discussion never runs more than about 60 calls, at which point it consumes about 125 000 file descriptors / handles in Asterisk
    (total open files in the kernel goes to about 195 000) – I thought this was normal….!

    Note that besides some timer problems that pop up occassionally (unsure if it is related) the box is totally stable and has spent days at 100 000+ open file descriptors operating Asterisk quite happily with no other problems save that when the binary started up for that run it did not have a sufficiently high file limit to actually work.

    Thanks for the reply!

    Kind regards,

    What the ‘h’ are you doing that takes x00,000 open files?

    I’m running Asterisk 11.17.0 on CentOS 6.7 and my ‘numbers’ seem insignificant by comparison.

    sudo /usr/sbin/asterisk -r -x ‘core show channels’ | grep active
    347 active channels
    344 active calls

    sudo lsof | wc -l

    sudo lsof | grep asterisk | wc -l

  • I vaguely recall potential leaks that caused excess file descriptor usage in older versions, but it’s so old that it’s hard to remember. Just to provide some scope of how many changes there are between even and 1.8:

    ✔ jcolp@electron:~/development/asterisk/public [11|⚑ 1]> git diff | wc -l

    That’s 221,688 changed lines.

    Joshua Colp Digium, Inc. | Senior Software Developer
    445 Jan Davis Drive NW – Huntsville, AL 35806 – US
    Check us out at: http://www.digium.com & http://www.asterisk.org