Install and Secure Redis on CentOS 7


Redis Installation

Add the EPEL repository, and update YUM


Install Redis


Start Redis and setup automatically start Redis on boot


Verify the Installation

If Redis is running, it will return: PONG


Redis Configuration

Password settings

find and uncomment the requirepass line in the configuration file, and replace master_password with a secure password


Firewall settings


Local Benchmark Test


Check Redis Version


Setup PHP session to Redis



Install wkhtmltopdf & wkhtmltoimage to CentOS with Chinese & Asian fonts support

Install dependencies


Install wkhtmltopdf and wkhtmltoimage

p.s. you can find more versions in the following link:


Install  Chinese & Asian fonts support



Add swap to CentOS without reboot

Add 4G swap


How to encrypt and decrypt .cpt file

What is .cpt extension?

.cpt is a encrypted file format, you can use ccrypt to create and decrypt .cpt file


How to encrypt and decrypt .cpt file

Encrypt a file

Decrypt a file.


How to install ccrypt

Install ccrypt on CentOS

Install ccrypt on Debian/Ubuntu


Install MySQL-Python (MySQLdb) on macOS

MySQLdb is an thread-compatible interface to the popular MySQL database server that provides the Python database API.

Standard Installation


EnvironmentError: mysql_config not found

You need install mysql and link, before install MySQL-Python


CentOS 7 unable to login, display login incorrect immediately after input login name


Unable to login linux console, always show login incorrect for any login name



Selected some security profile(e.g. PCI-DSS) during installation, but network connection is unavailable.

Installer unable to download some packages from the internet, and caused installation failure. You may feel the installation time longer than no security profile.


In my case is CentOS installer missing the web proxy settings 🙁


How to Fix

Select other security profile or setup correct network connection, and re-install the system.



CentOS-7 Installer Security Profiles

2.1. Requirements

These profiles require a connection to the internet to install. If you select a security profile that can not connect to the internet on port 80 (to, your install may fail spectacularly and not even allow access to the console locally. Please only try these profiles while connected to the internet.

Packages will be installed from the internet if you use security profiles, even if those packages also reside on the ISOs.


How to Install ffmpeg on RHEL/CentOS 7

Install ffmpeg via ATRPMS repo


Try convert WAV file to MP3 format