System Notes Org

Server Availability cannot always be checked by using ping, since often a secured subnet will not allow traffic back.  That common practice of dropping packets is an attempt to hide servers and provide additional security, but it can make troubleshooting more difficult. Since ssh is typcially running and responding on any linux servers that need to be managed, check_ssh seems to be more practical than the default check_ping as the check_command for each host definition in Nagios. This simple shell script uses a Nagios plugin /usr/local/nagios/libexec/check_ssh to quickly check the status of a server.  One thing to note is that a Nagios installation is not required, just the plugins have to be compiled so the binary can be available to the wrapper script. #!/bin/sh # checkssh.sh # # Author: Scott McClelland # 2017-03-29 # # checkssh, uses Nagios plugin check_ssh # /usr/local/nagios/libexec/check_ssh # # nagios-plugins are downloadable from: # https://www.nagios.org...

I wrote some shell scripts to generate Nagios configuration files, and I finally decided to publish them on Freshmeat . The initial version is crude, and has some hard-coded information, but it is still better than trying to edit the .cfg files by hand. Here is a brief description nagios-config-build is a group of shell scripts that generate Nagios configuration files from a list of hostnames. It automatically resolves IP addresses from DNS, and provides a quick way to manage a large number of hosts without having to set up a complicated system. Nagios is more than just a server monitoring tool. From the Nagios website: " Nagios is a powerful monitoring system that enables organizations to identify and resolve IT infrastructure problems before they affect critical business processes." Systemnotes.org download: http://www.systemnotes.org/download/shell/nagios-config-build.html Freshmeat project: http://freshmeat.net/projects/nagios-config-build Please feel free to use thi...

I explained how to get a list of hosts using nmap -- using-nmap-to-generate-host-lists.html , but here is another look at the subject. The question is, how do I ping multiple hosts to find out which ones are down? Sure this could be considered a topic of system monitoring, but maybe you just want to reboot a bunch of machines, and make sure they all come back online. This quick check will tell you whether there is a problem or not. Here are three methods for pinging a list of hosts: 1.) for host in `cat all.txt `;do ping -c 1 $host; done 2.) nmap -sP -R -iL all.txt 3.) sudo fping -u < xyz/all.txt First, we assume that you have a text file named all.txt that contains a list of hostnames, one per line. Obviously, the examples here contain fake hostnames, domain names and IPs, as described in another article about vi: vim-tips-search-and-replace.html . --- all.txt --- xyz-1 xyz-2 xyz-3 xyz-4 xyz-5 xyz-6 xyz-7 xyz-8 --- end all.txt --- 1.) Use a for loop in ...