Category: Articles

Troubleshooting Sendmail

Check Your IPAddress to see if it is black listed

Sometimes, you think you should be receiving email from your linux host but the email messages never come. You have verified the email address, you have installed different email program variants, sendmail, mail, mutt, etc…, and yet the messages still…

Configure ODBC for MySQL on CentOS

Migrate Users from MySQL to MySQL

We have already installed ODBC drivers for Oracle and PostgreSQL in prior articles.  In this article, we will install ODBC drivers on CentOS to connect us to an MySQL database.  The general idea is similar to the steps we followed…

Nginx or Varnish Which is Faster?

Nginx or Varnish Which is Faster?

I have been working with Nginx and Varnish for a good little bit.  They are both obviously great proxy servers.  The question that I have asked myself and others over this time is which should I actually use?  Which performs…

Configure Sftp with User Jails

So, at your organization there is a high likelihood that you will need to create an FTP server to allow your customers and vendors to send you files.  While having an ftp server is useful and all, the old standard…

More Salt Notes – Targeting Minions

Use Salt to Manage all of your Salt Minions

In an earlier article (Puppet, Chef, and now Salt for Configuration Management), we discussed how to install salt for configuration management.  At the end of the article, we discussed running command on the minions using the salt command from the…

Using the MySQL Binary Log

MySQL Point in Time Recovery

Enabling and managing binary logging will make it more likely that you can recover your database to a specific point in time.  These point in time recoveries require proper backups as well as having your MySQL server instance configure for…

Killing Linux Processes

Killing Linux Processes with TERM Signals

From time to time, if you are a Linux Administrator, you will have to kill a linux process.  The linux kernel has at least 32 signals.  Amongst those 32, you may recognize some of the more common ones:  SIGTERM, SIGHUP,…

PostgreSQL Replication

PostgreSQL Replication Options So, with all of the other articles that I have written about Postgresql, I figured that it was inevitable that we finally get one written about replication.  What makes an article about Postgresql replication difficult is that…

Upgrade Postgresql 9.2 to 9.3

If you installed Postgres using the methodology demonstrated in our earlier article:  CentOS Install Postgres 9.3, then at some point you may need to upgrade your Postgresql instance.  For this article on upgrading postgresql, I used a 9.2 instance that…

Free IT Job Postings

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Benchmark Your Webpage with Siege

Benchmark Your Webpage with Siege

A few articles ago, I wrote about using the “apachebench” or “ab” utility to benchmark your website (see:  apachebench).  Ab is a great tool, but since then, I have found and fallen in love with a new tool for benchmarking…

Upgrading to vCenter Appliance 5.5

vSphere Web Client Login

Let me begin by saying that most people running the vCenter appliance are typically using Essentials versions of VMware.  This example case is using VMware Essentials Plus.  In smaller VMware installations, it is simpler to install a new version of…

Speed up Your WebPage with Varnish

Varnish Can Seriously Speed up Your Webpage's Performance

Using Varnish Caching and Proxy If you have a website with lots of static objects like http://uptimemadeeasy.com, then it is likely that you can save some performance by caching those static objects in a memory so that when they are requested,…

Monitor Postgresql with Nagios

Monitor Postgresql Connections with Nagios

The other day, we had an issue with one of our PostgreSQL databases where one of our applications wasn’t closing its unused connections. We tripled the max_connections and it used all of those up too. While I was monitoring the…

Install Nginx on CentOS

Install a Simple Nginx WebServer

There are many ways to Install Nginx on your CentOS machine, but whenever possible, I will try to install using a repository and yum whenever possible.  If you wish to install Nginx, there are a couple of different repos that…

Install Cacti on CentOS 6

Install Cacti On CentOS 6

Cacti is a great tool for graphing almost anything that talks SNMP. You can use it to graph server performance, file system usage, router interfaces, bandwidth usage, temperature, etc…  Because so many have created their own templates for it, there…

10 Helpful Postgresql Commands

Here are some more helpful postgresql commands that can help your out in your first few weeks of using Postgresql.  Finding the current, time, which database you are in, the size of a database or a table, the database ipaddress…

CentOS Install Postgres 9.3

Postgresql is a great SQL database with lots of great features that you can install for free with just a few quick tasks.  First, we need to get the yum repo from postgresql website, use yum to install it and…

Apache File Cache Module

Monitor Apache Processes at http://uptimemadeeasy.com

If you don’t have a CDN and would like to improve the performance of some of your webpages, you can easily do it using Apache File Cache Module.  Apache’s file cache module allows you to specify specific images and files…

Monitor Apache Usage

Monitor Apache Processes at http://uptimemadeeasy.com

Get Detailed Performance Information from Apache You may be looking for a microscope into your Apache httpd service to see how many users you have using it, get performance information, and see the current individual Apache httpd processes and what…

Monitor Apache Processes

Alert Yourself of Cyber Attacks Ok, this article will not alert you to all cyber attacks, but I wrote this script to help me identify huge changes in traffic to my websites and while it isn’t perfect, it has done…

Resolve Passive FTP Data Port Problems

Configure Passive FTP Server with VSFTP Firewalls attempting to protect their workstation clients behind them make it nearly impossible to use active FTP for transferring files because the firewall will not allow the server to initiate the data port to…

Configure Apache Access_Log Format

Configure Apache Access_Log Format

The Apache access log is one of the most important files that you can use to create reports on your visitor’s behavior to your website.  I often use Awstats (See:  http://awstats.sourceforge.net/ ) and other reports on my Apache access_log files. …

Setup NTP on CentOS Linux

Set Your Server's Clock with NTP

What is NTP? NTP (Network Time Protocol) is the time protocol that most servers in the world use to keep in sync.  Most companies will have a local NTP server that they keep in sync with an external timing source…

Install VNC Server on Linux

Connected with VNC

Setup a Remote GUI on Linux Using VNC Server There are some times when having a remote GUI console can be very helpful.  You may want to use the GUI interface for configuring the machine or to use applications.  I…

Linux Snapshot Backups

Creating Linux Snapshot Backups

Uptime vs Database Backups Backups of your database can be an enemy to your system uptime.  Doing a filesystem dump of your database tablespace files will require that it occur while your database is down so that you don’t have…

MySQL Master / Slave Replication

Master Slave MySQL Replication Summary Master / Slave replication in MySQL is a great way to store an exact replica of your database on another machine in another location as part of a disaster recovery plan.  Before setting up Master…

Nagios Remote Plugins with NRPE

Nagios: Setup Nagios NRPE

Nagios Remote Plugins with NRPE Two weeks ago, we setup Nagios in the article: Monitoring Your Systems with Nagios and last week, we defined Nagios hosts and services in the article: Configure Nagios Hosts and Services.   This week, we will…

Configure Nagios Hosts and Services

  Now that you have Nagios installed (See last week’s article:  “Monitoring Your Systems with Nagios” ), you are ready to begin monitoring services such as ssh, websites, and other services.  So that brings us to the purpose of this…

Joining Buildings with Fiber

Network Challenge – Connect Two Buildings I have had to extend my network into a second building two times in the last several years.  The first time I got lucky.  Although there was no fiber to the building –to either…

Setup DynECT Dynamic DNS

There are some things in life that don’t make any difference to you when everything is good.  But suddenly make you happier when there is a problem.  For me, DynECT Managed DNS traffic management is one of these.  It doesn’t…

Create a SonicWall SSLVPN

SonicOS Version There are several great tutorials out there on how to setup a SonicWall SSLVPN.  Each one is somewhat different as the SonicOS changes and the steps and location of items changes from release to release.  So, while they…

Choose a Link Balancer

ISP Outage Anybody with any IT experience will tell you that at some point, you will have ISP issues. Depending on the issue you could be down anywhere from just minutes to hours. I once had an issue with a…

Install Ruckus Wireless

DIY Wireless The simplest multi-access point wireless installation that I have ever installed was to install Ruckus Wireless gear.  I stumbled across Ruckus by reading comments in spiceworks forums , and from those who used it for their own network. …