Now I already have EOSIO Private Blockchain for 4 VM Server (Ubuntu Server 18.04 TLS) for nodeos and 1 Wallet (Keosd) in Client (Ubuntu Server 18.04 LTS) as diagram below
All Machine install EOSIO Software and CDT by compile from Source Code according to Official Document from https://developers.eos.io/eosio-nodeos/docs/autobuild-script
But I’m not sure if upgrade EOSIO in VM Server (All 4 Nodes) from current version to newer version in future. It’s need Data Migration or not. Please advise me because I tried to search in web site and internet before but not found clearly answers.