Lots of you may have encountered some error message stating that the port has been taken by another program while trying to start a program on Linux. And you would want to know which program takes the port you want to use. This post will provide some feasible ways to check out which program is taking a specific port.lsof -i:[port]lsof is the command to list open files on Linux. And if you know more about Linux you should get to know everything on Linux is a file even including network connection. Hence you can use lsof to list the network programs which are running.The -i option will...

As a system administrator or network engineer or application developer, there is a need to check whether a port on remote server is open so that you can tell whether the service under check is running or not. In this post, we would cover a few methods to check whether a remote server port is open or not on Linux.telnettelnet is the most frequently used command on both Windows and Linux to check port. The simple usage for this command is telnet [host] [port]When the port is open, the output will be like:Trying 192.168.56.160...Connected to 192.168.56.160.Escape character is '^]'.SSH-2.0-Op...

When a Linux server is running, it has to have an IP so that other machines can talk to it. It is often desired that the server would own a static IP so that every time other machines want to connect to it, the same IP address would be used. This is extremely useful when there are virtual machines installed on a host machine where the virtual machine would start and stop now and then. To configure static IP address for a Linux server, the /etc/network/interfaces needs to be updated. Assuming there is a host only network is created for a network interface named eth1. The configuration woul...

There are two ways to install Oracle database on Linux :1). Using GUI; 2). Using response file. In this post, the method for using response file will be introduced.To install Oracle, please first get the Oracle database installation file ready. It can be downloaded from Oracle OTN. You need to have an Oracle account before you can download them.And there are three major components of the Oracle database installation : 1). The installation itself; 2). The network configuration; 3). Database creation. Each of the component can be completed with a response file. There are sample response files in...

After login to a Linux system, the command console will show up with a prompt label such as # or ~, a shell command can be typed after this prompt and the system can execute the command thereafter. All these operations are handled by shell.Shell is a command language interpreter that executes commands read from the standard input device (keyboard) or from a file. There are different types of shells such as bash, ksh, csh etc. The most commonly used of them is bash and it's also the default one on most Linux distributions.There are two very important configuration files for bash : bas...

As a beginner user of Unix or Linux, people would frequently get confused about the use of different directories of the system. For example, there is a /bin directory under root(/), it is used to store binary files. However, there are /usr/bin and /usr/local/bin under /usr which are used for storing binary files as well. Some systems even have /opt/bin. What are the differences among them?Though there are articles explaining different directories in *nix such as Filesystem Hierarchy Standard, it's not clear why these directories are present and their history. Rob Landley filled part ...

On Oct 2, Linus Torvalds proudly announced the release of Linux 4.8. But just days after the release, a bug was found in the kernel and Linus came out and apologized for this bug.I'm really sorry I applied that last series from Andrew just before doing the 4.8 release, because they cause problems, and now it is in 4.8 (and that buggy crap is marked for stable too).In particular, I just got this kernel BUG at ./include/linux/swap.h:276 and the end result was a dead kernel.The bug that commit 22f2ac51b6d64 ("mm: workingset: fix crash in shadow node shrinker cau...

SSH is a popular cryptographic network protocol for secure network service operation. It is frequently used in remote server login. For a system administrator or software developer, SSH is frequently used to access remote servers or development servers or testing servers etc. To login with SSH, there are different authentication mechanisms : password, public key and interactive etc. If a remote server needs to be accessed frequently, password authentication may be too troublesome as password needs to be typed every time. In this scenario, public key authentication would be a life sav...