Servers Archives - j2sw Blog

DNS in ISP networks and why you should care

If you are not familiar with how DNS works, please go and read this article and watch the accompanying video. In this article we will talk about the different types of DNS servers an ISP will encounter and the design considerations of implementing them into your network. Let’s jump into the three types. Cache servers local DNS (LDNS) servers authoritative DNS (ADNS) servers, of which the Root and Top Level Domain (gTLD) servers are special cases Let’s go into detail on what each...

RAID Drive level comparison

Quick chart showing the differences between different raid levels in servers and storage.

November 10, 2021 by j2sw Equipment Servers

DNS shotgun for DNS testing

DNS Shotgun is capable of simulating real client behaviour by replaying captured traffic over selected protocol(s). The timing of original queries as well as their content is kept intact. https://dns-shotgun.readthedocs.io/en/stable/key-concepts/

April 6, 2021 by j2sw Servers

Server Tip from a non-server guy

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March 8, 2021 by j2sw Servers Tips

LibreNMS syslog.ibd cleanup

Recently I ran into an issue where a librenms install was taking up a crazy amount of disk space. This was tracked down to the syslog.ibd file . Even thought I had set my options to be less than 10 days per this link https://docs.librenms.org/Support/Cleanup-options/ I still was having a huge file. Here is what I did to fix it. My root partition was too full to start MariaDB. I went into var and cleaned out enough log files to make space to...

March 1, 2021 by j2sw Servers

PHP 7.3 and 7.4 Woes and solution

So this weekend I have been doing some LibreNMS installs and have been having to change the default CentOS PHP version. If it is Centos7 PHP 7.3 is recommend and if it’s Centos 8 then PHP 7.4 is recommended. I have some pretty good tutorials on installing Librenms that I follow. They all mention the remi repository. However, on a few of these networks the remi repository has been unreachable. So I just can’t cut and paste from the tuorials I use. So...

December 7, 2020 by j2sw Servers

Some WordPress tips

If you are wanting to force non SSL to SSL. Add the following to your site’s .htaccess file Set proper file permissions Script from https://www.ryadel.com/en/set-file-system-permissions-wordpress-web-site-centos-7-chmod/ # # This script configures WordPress file permissions based on recommendations # from http://codex.wordpress.org/Hardening_WordPress#File_permissions # # execute it with the following command: # bash set-wordpress-permissions.sh /var/www/<site_folder> # OWNER=apache # <– wordpress owner GROUP=www # <– wordpress group ROOT=$1 # <– wordpress root directory # reset to safe defaults find ${ROOT} -exec chown ${OWNER}:${GROUP} {} \; find ${ROOT}...

July 2, 2020 by j2sw Servers Tips