How to host multiple websites in a single VPS in LAMP environment. All sites will use SSL certificates (https). All commands are for shown considering Ubuntu linux.
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Multiple WordPress with SSL in Ubuntu 16.04
Complete guide to host multiple WordPress sites in a LEMP stack in a Ubuntu 16.04 LTS. Installation of SSL by Let’s Encrypt has been illustrated also.
How to Create Multiple SFTP User in VPS
Create multiple SFTP user in a VPS for accessing respective website folders. Access is limited to the respective folders only. Use FileZilla to access remote Host.
MySQL Commands for Hosting in Linux VPS
You need to copy olddb.sql file to your new host. You may use FTP programme to download the SQL file from old host and then upload to the new host.