I recently had some trouble with my postfix mail service. Not knowing where to being looking for log files and restart commands, I thought this quick cheat sheet would come in handy in the future: Starting and Stopping On CentOS we can speak to postfix like this: postfix start postfix stop postfix reload The this … Read more
I’ve just launched an EC2 instance from my own AMI. This time however I wanted it to have more storage so I increased the size of my disk space from 10 to 100GB. Once the instance had launched I’ve noticed that – as before – only 10GB was actually available. I’ve had this with other … Read more
Bind Mounting allows us to make one directory accessible from more than one location. It’s like “intercepting” directory1 and making the system redirect requests to directory2. Let’s take a look how to set this up and why we may want to use this technique. Quick Refresher: Device Mounting Perhaps you’re familiar with mounting devices to … Read more
I was pulling my hair out the other day trying to connect to a VM in Parallels Desktop. It’s fairly straightforward, yet rather complex at the same time. Here’s how to do it step by step. In this example I’m running Parallels Desktop 8 under Mac OS X 10.9 Mavericks, and my Guest OS CentOS … Read more
Did you know that you can run PHP directly from the command line? Here’s how: Running a command Let’s run a one-liner and see the output displayed in our console. We’ll use phpinfo() because we know it should generate a lot of text. We need to start our line with php, use the -r switch … Read more
I’ve just tried to update one of my CentOS 6.2 servers that was built from an older AMI, only to find that the yum update command stopped unexpectedly with several dependency errors. They all pointed to something called “qpid”, and I must admit that I’ve never heard of it – nor did I know that … Read more
Version 6.x of Apple’s AirPort Utility displays all your wireless client’s IP addresses, but it doesn’t show you wired devices. The old version 5.6 did, but without a hack it no longer runs on Mountain Lion. There is however a simple way to display all clients using the command line tool arp. Open up a … Read more
yum can help us here. This should do the trick: #yum list installed If you’re interested in a particular package, you can pipe a search string into grep and only list filtered results: #yum list installed | grep “yum” keyutils-libs.i686 1.4-4.el6 @anaconda-CentOS-201303020136.i386/6.4 yum.noarch 3.2.29-40.el6.centos yum-metadata-parser.i686 yum-plugin-fastestmirror.noarch The search string doesn’t even need to be in … Read more
