All posts tagged CentOS


I just released a set of scripts that come in handing when creating clean images for virtual environment, heck you can even use it for cloud images.

What they do is:

  • clear all the logs
  • clean up the networking scripts, because the normally get references to the mac address in CentOS
  • clean up the repository files
  • in some cases create a root user

There are scripts for: CentOS 6, Debian and OpenSuse.

They can be be found in the tools section or in github.

snmp errors in syslog

I finally got fed up of these messages in my log files (/var/log/messages) and decided to do something about them:

Apr 19 04:14:47 hostname snmpd[3458]: Connection from UDP: []:42482
Apr 19 04:14:47 hostname snmpd[3458]: Received SNMP packet(s) from UDP: []:42482

After reading, googling around and testing for a while I rounded it the following solution, it should work in any Linux system with net-snmp after some tweaks but out of the box on CentOS, REL, Fedora or any of its relatives:

1. Remove the -a from the snmpd start options or write this in the /etc/sysconfig/snmpd.options file:

OPTIONS=”-Lsd -Lf /dev/null -p /var/run/”

This should take care of the “Received SNMP” packets line (2nd one).

2. Add dontLogTCPWrappersConnects true at the end of your /etc/snmp/snmpd.conf file, that takes care of the other line:

Apr 19 04:13:47 dcf-is1p snmpd[3458]: Connection from UDP: []:48911

According to the man page: This setting disables the log messages for accepted connections. Denied connections will still be logged.”

The problem is that the default settings are to log every connection / request, so what we did was leave the log work only for failed and authenticated attempts

Enjoy readable logs!