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.


MySQL ERROR 1366 (HY000): Incorrect integer value: ” for column ‘id’ at row 1 Problem & Fix



MySQL throw the following error message on insert or update statement executed



Try to update string value into integer column, and strict sql mode is enabled.

Mainly occurred on MySQL 5.x or above.


How to Fix:

1. Disable strict sql mode

Update /etc/my.cnf , and remove STRICT_TRANS_TABLES from sql-mode



Too many process sidekiq 4.2.7 gitlab-rails [0 of 25 busy]

I am running a small GitLab server for my personal use, but GitLab default concurrency settings up to 25.

So I try to update the max concurrency to free server resource.


Update Configuration

Add or update the value


Restart the Service



Most Simple and Fastest Way to Backup and Restore a MySQL Database (mysqldump & mysql client)

How to mysqldump and mysql to backup and restore a database:

Backup to .sql file


Restore from .sql file


Suggested to run the command in database server to get the fastest speed.



How to Install ffmpeg on RHEL/CentOS 7

Install ffmpeg via ATRPMS repo


Try convert WAV file to MP3 format