Ubuntu is one of the most user friendly distributions of Linux operating system. If you want to do PHP and MySQL development on an Ubuntu based machine or want to host an application developed in these technologies on a virtual server that runs Ubuntu, then you will first need to install the LAMP stack on that system.
Fortunately, it is very easy and simple to do so. First of all, update your repositories:
tasksel . It is a helper program that provides easy installations for a number of related software packages, one of which is LAMP stack.
sudo apt-get install tasksel
It might be already installed on your Ubuntu distro, as was the case on my DigitalOcean droplet. Now, run tasksel. Continue reading
Yesterday, I was trying to setup Apache Tomcat 7 on Ubuntu 14.04 on a new DigitalOcean droplet. But it was taking VERY long (10-15+ minutes) to serve first request. After that, it started serving requests normally. If the Tomcat was restarted, it again took very long to serve the first request.
I tried large droplets with more memory. Also, I tried installing Tomcat from both the Ubuntu repository package and from official Tomcat website. But in every case, I faced the same problem.
Turns out, the solution is pretty simple. We just need to install a package named
haveged like this:
sudo apt-get install haveged
Now restart Tomcat and you will see that it starts serving requests immediately at normal speed.
Basically what happens is that the entropy pools run dry on our virtual server running in the cloud. As a result, Tomcat blocks on
/dev/random waiting for random numbers to be generated. Haveged seeds our system’s random source (usually /dev/random) using differences in our processor’s time stamp counter (TSC) after executing a loop repeatedly. Please refer to this article on DigitalOcean for details of this process.
Do you need to find out if your Linux installation is 32 bit or 64 bit? I usually need this information when manually installing a piece of software (e.g. Netbeans Profiler Remote Pack).
There are two alternative commands which produce identical output. You can use any one of these:
If any of these commands outputs
x86_64 then your Linux is 32 bit. On the other hand, if the output is
i386 then you are running a 64 bit Linux distro.
For detailed discussion of these and some other useful, related commands, please checkout: http://www.howtogeek.com/198615/how-to-check-if-your-linux-system-is-32-bit-or-64-bit/
In this article, I will walk you through the process of configuring your local, Ubuntu based development machine to send emails from within PHP and also from the command line terminal. In a nutshell, you need to install and configure a mail server on your local computer. The mail server that we are going to use is Postfix. So without any further delay, lets get started.
Open up the terminal and, first of all, enter the following command:
sudo apt-get install mailutils
It will make available the “mail” command on your terminal and also will install all the programs that it depends on. Our desired mail server Postfix is one of them. During installation, accept the defaults as configuration options of Postfix when asked.
Once the installation is complete, type following command:
sudo dpkg-reconfigure postfix
I am running Ubuntu 13.10 64bit on my Lenovo G500 laptop. I was facing a strange problem. Whenever my laptop went to the suspended state and I resumed it afterwards, its touchpad was not working. A little bit of Googling returned a simple solution that worked like a charm. I am summarizing that solution here in this post for future reference of me and anyone else facing a similar problem.
Open up the terminal and type following command:
sudo -i gedit /etc/pm/sleep.d/0000trackpad
It will create a new file named “0000trackpad” in the /etc/pm/sleep.d/ directory and subsequently open it for editing in gedit. Paste following code snippet in this window, save the file and close it.
case "$1" in
modprobe -r psmouse ;;
modprobe psmouse ;;
Back to the terminal, type following command to make the newly created file executable:
sudo chmod +x /etc/pm/sleep.d/0000trackpad
And … that’s it. Above steps solved the problem for me and hopefully will do the same for you too. Suspend/Resume your laptop a few times to make sure that your touchpad no longer gets disabled automatically.