[HOW TO] install erlang, elixir on CentOS 6

Roughly 30 minutes ago I installed Erlang & Elixir into our server. It doesn't matter for everyone but until when everyone need help lolz. So I write down the shortly instruction below.  I. What is erlang & elixir?  Please google to know it. II. How to install? Please ensure wget already installed on your server. The next commands retrieve a package that adds a new repository...

[HOW TO] set umask for user has /sbin/nologin environment

Come back to the last week, I worked on case "change umask for SFTP/ SSH user" At that time, I simply thought that it is umask. So I added umask to ~/.bashrc and ~/.bash_profile. But nothing to change. It means that I need think logically. User login -> ssh -> pam.d/ssh -> /etc/profile (~/.bash_profile) Why?  A few second I see that user's ssh/ sftp has shell environment is /sbin/nologin....

[HOW TO] check slot RAM information on Linux Operating System

One day you need to increase memory for physical server at Data-center. But you can't shutdown it to check the available slot. What's up next? Luckily if you are using Linux Operating System. Because Linux has dmidecode to check hardware information. I will tell you about dmidecode. In general you need to deeply understand what are you doing. I learned this mythology by my close friend. dmidecode...