On Mar 10, 2017 2:59 AM, "vijay amruth" <vijayamruth@gmail.com> wrote: Hello everyone, Hope you are all doing great. I am running into some issues with syslog-ng file descriptors, I have tried to set up ulimit -n value to 65535, *open files (-n) 65535* set the parameter to the follwoing in /etc/sysctl.conf, *fs.file-max = 512000* and tried raising the value with syslog-ng --fd-limit <number>, I get the following error ####syslog-ng --fd-limit 8192 WARNING: Configuration file format is too old, syslog-ng is running in compatibility mode Please update it to use the syslog-ng 3.5 format at your time of convinience, compatibility mode can operate less efficiently in some cases. To upgrade the configuration, please review the warnings about incompatible changes printed by syslog-ng, and once completed change the @version header at the top of the configuration file.; WARNING: global: the default value of log_fifo_size() has changed to 10000 in syslog-ng 3.3 to reflect log_iw_size() changes for tcp()/udp() window size changes; Using a global log-fetch-limit() option was removed, please use a per-source log-fetch-limit(); WARNING: window sizing for tcp sources were changed in syslog-ng 3.3, the configuration value was divided by the value of max-connections(). The result was too small, clamping to 100 entries. Ensure you have a proper log_fifo_size setting to avoid message loss.; orig_log_iw_size='0', new_log_iw_size='100', min_log_fifo_size='1300000' These errors are not related to the FD limit setting, rather it tries you that your config version is older than your syslog-ng version, and as number of changes were made since the version you were previously using. You should either remove the offending options, or adjust their value. log-fifo-size needs to be at least 10000 log-iw-site should probably be removed log-fetch-limit should probably be removed as well. Once you are done with these changes, increase @version at the top of the file, then the warnings should be gone. The FD limit is probably set properly, the warnings had nothing to do with that. You just need to make sure to add this parameter to the startup options. and I am unable to stop the syslog-ng service using systemctl, it immediately re-starts, I am using centOS 7.2, I have noticed few other people on the internet had the same problem, please advice, any help is appreciated. *OS: CentOS 7.2* *Hardware : VM* *Problems : 1) Unable to increase the file descriptors for syslog-ng. 2) Unable to stop the service using systemctl stop command, it automatically restarts right after with a new pid.* You seem to be using 3.5.x please upgrade to 3.9.1. We did a number of improvements wrt systemd in recent versions.