Articles in the System Administration category

1. What's Next? Using Chrome OS and Crouton For Work

   Posted on November 09, 2015 in System Administration

   It is well-documented that I am a heavy Google user. I use Gmail and Google Docs for just about everything. Additionally, I have used an Android phone since I got the HTC Dream (AKA T-Mobile G1) when it first came out.

   However, I have been using OS X full-time since …

2. Redis: Better Session Storage for Magento

   Posted on October 28, 2015 in System Administration

   Out of the box, Magento has four methods available for storing session data: filesystem, database, memcached, and tmpfs. The default method is to store session information in the filesystem. I believe that storing sessions in Redis is actually superior to all of the aforementioned methods. Each of the four default …

3. El Capitan Leads to More DNS Woes

   Posted on October 06, 2015 in System Administration

   For whatever reason, Apple really likes messing with how I use DNS.

   I've written many, many, many times about having to modify OS X's DNS functionality to append search domains when a hostname includes a dot. Every single time I upgrade, this change is broken.

   Previously, the workaround had been …

4. nginx: Blocking Access to /xmlrpc.php

   Posted on July 31, 2015 in System Administration

   I recently ran into an issue on a Wordpress site running behind an nginx web server. The site was frequently being attacked by a botnet hitting /xmlrpc.php so rapidly, it would eventually force the FastCGI processes behind nginx to consume all available CPU. Naturally, this would cause all legitimate …

5. Goodbye, discoveryd. Hello again, mDNSResponder.

   Posted on July 07, 2015 in System Administration

   Great!

   Once again, Apple has made a change in how DNS is handled in Mac OS X. Originally, Yosemite (10.10) had replaced mDNSResponder with discoveryd. This meant that all of those who had made a change to force mDNSResponder to always append search domains to DNS lookups had to …

6. Why Isn't tmpreaper Working?

   Posted on April 20, 2015 in System Administration

   If you have a directory that you want to keep clean, tmpreaper is a great way to remove files based on how old they are. The other day, I had a directory that looked like this:

   x@x:~/dump$ ls -l
   -rw-r--r-- 1 x x 212268169 Mar 15 01:02 …

7. WARNING: The following packages cannot be authenticated!

   Posted on December 18, 2014 in System Administration

   We run several (read: hundreds) of servers that are still running Debian 6 (Squeeze). A few months ago, we started seeing the following errors coming from the daily apt cronjob: "WARNING: The following packages cannot be authenticated!" When running apt-get update the following errors dump out:

   $ apt-get update
   W: GPG …

8. OS X Not Appending Search Domains - Yosemite Edition

   Posted on November 20, 2014 in System Administration

   It seems this problem has resurfaced again with the new version of Mac OS X. More specifically, this problem seems to affect appending search domains when the hostname contains a dot. In Yosemite (10.10), mDNSResponder has been replaced with discoveryd. Fortunately, all we need to do here is add …

9. Mac OS X Not Using Search Domains

   Posted on May 04, 2014 in System Administration

   Every time I restart my OS X Mountain Lion (10.9) laptop, it stops using the DNS search domains I've added via the Network preferences pane. I have found that restarting mDNSResponder fixes this issue. There are two ways to do this.

   The first is a simple restart by sending …

10. Puppet + Augeas: Modify Logrotate Configuration

    Posted on March 12, 2014 in System Administration

    On my web server, I keep my web sites in /var/lib/www. Each web site has a dedicated logs directory. Since logrotate is already rotating Apache logs on the server, I'd like to continue using that to rotate these log files as well. Below, is a Puppet snippet that …