How to enlarge CentOS 7 persistent disk size in Google Cloud

Update Disk Size

Update Partition Size

Update Volumn Size



Auto Launch Chrome in Kiosk Mode/Fullscreen Mode with specified URL on macOS Startup

Setup Steps:

  1. Start
  2. Select Application
  3. Click Show library in the toolbar (if hidden)
  4. Add Run shell script (from the Actions/Utilities)
  5. Paste the script into the script window
  6. Test run
  7. Save somewhere (for example you can make an Applications folder in your HOME, you will get an
  8. Go to System Preferences -> Accounts -> Login items
  9. Add this app
  10. Try reboot

Kiosk Mode Script

Fullscreen Mode Script


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



How to fix MySQL connection error: Authentication plugin ‘caching_sha2_password’ cannot be loaded: dlopen(/usr/local/mysql/lib/plugin/, 2): image not found

The problem is some MySQL clients not yet support new password encryption method.


Just change the user password encryption back to legacy version, then problem will be fixed.

The following SQL update specific user to legacy encryption:


Also, you can change the default authentication plugin to legacy version.

Update /etc/my.cnf and add the following line after [mysqld]:



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