CentOS7にBitnamiRedmineを導入し。運用中にエラーが発生

###前提・実現したいこと
ローカル環境にVirtuarlBoxを導入し、CentOS7環境を立てて本番サーバへの導入前検証を行っています。
検証中にエラーが発生し対処しましたが、Mysqlのユーザパスワードが変わった原因が知りたいです。

簡単にではありますが検証で行っていたこと
0. VirtualBox上のCentOS7環境にbitnami-redmine-3.4.2-3-linux-x64を導入
0. BitnamiRedmineをしばらく運用し、データが蓄積される
0. データの引っ越しが発生することを想定し（サーバ移管とかバージョンアップ）BitnamiRedmineのデータバックアップ
0. BitnamiRedmineを入れ直してバックアップデータを流し込む（SQLのInsert文とFilesフォルダの中身）
0. 再度運用開始させて運用開始と思っていた所でエラーが発生
0. エラーログよりMysqlのログインに失敗していると判断、Mysqlのログインユーザパスワードを変更
0. firewallの設定がおかしいのかと思いfirewallの設定見直し
0. エラーは解消され動作するようになった

###発生している問題・エラーメッセージ

[ 2017-09-26 10:49:47.3904 14724/7f8f0f335700 age/Cor/App/Implementation.cpp:304 ]: Could not spawn process for application /opt/redmine/apps/redmine/htdocs/: An error occurred while starting up the preloader.
Error ID: 09d4ab6f
Error details saved to: /tmp/passenger-error.2wygBk
Message from application: Access denied for user 'bitnami'@'localhost' (using password: YES) (Mysql2::Error)
/opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/mysql2-0.4.9/lib/mysql2/client.rb:89:in connect' /opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/mysql2-0.4.9/lib/mysql2/client.rb:89:in initialize'
/opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/activerecord-4.2.8/lib/active_record/connection_adapters/mysql2_adapter.rb:18:in new' /opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/activerecord-4.2.8/lib/active_record/connection_adapters/mysql2_adapter.rb:18:in mysql2_connection'
/opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/activerecord-4.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:438:in new_connection' /opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/activerecord-4.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:448:in checkout_new_connection'
/opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/activerecord-4.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:422:in acquire_connection' /opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/activerecord-4.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:349:in block in checkout'
/opt/redmine/ruby/lib/ruby/2.3.0/monitor.rb:214:in mon_synchronize' /opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/activerecord-4.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:348:in checkout'
/opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/activerecord-4.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:263:in block in connection' /opt/redmine/ruby/lib/ruby/2.3.0/monitor.rb:214:in mon_synchronize'
/opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/activerecord-4.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:262:in connection' /opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/activerecord-4.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:571:in retrieve_connection'
/opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/activerecord-4.2.8/lib/active_record/connection_handling.rb:113:in retrieve_connection' /opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/activerecord-4.2.8/lib/active_record/connection_handling.rb:87:in connection'
/opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/activerecord-4.2.8/lib/active_record/model_schema.rb:230:in table_exists?' /opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/activerecord-4.2.8/lib/active_record/attribute_methods/primary_key.rb:97:in get_primary_key'
/opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/activerecord-4.2.8/lib/active_record/attribute_methods/primary_key.rb:85:in reset_primary_key' /opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/activerecord-4.2.8/lib/active_record/attribute_methods/primary_key.rb:73:in primary_key'
/opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/protected_attributes-1.1.4/lib/active_record/mass_assignment_security/attribute_assignment.rb:15:in attributes_protected_by_default' /opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/protected_attributes-1.1.4/lib/active_model/mass_assignment_security.rb:337:in block in protected_attributes_configs'
/opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/protected_attributes-1.1.4/lib/active_model/mass_assignment_security.rb:222:in protected_attributes' ＜中略＞ /opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/railties-4.2.8/lib/rails/engine.rb:616:in block (2 levels) in class:Engine'
/opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/railties-4.2.8/lib/rails/engine.rb:615:in each' /opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/railties-4.2.8/lib/rails/engine.rb:615:in block in class:Engine'
/opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/railties-4.2.8/lib/rails/initializable.rb:30:in instance_exec' /opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/railties-4.2.8/lib/rails/initializable.rb:30:in run'
/opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/railties-4.2.8/lib/rails/initializable.rb:55:in block in run_initializers' /opt/redmine/ruby/lib/ruby/2.3.0/tsort.rb:228:in block in tsort_each'
/opt/redmine/ruby/lib/ruby/2.3.0/tsort.rb:350:in block (2 levels) in each_strongly_connected_component' /opt/redmine/ruby/lib/ruby/2.3.0/tsort.rb:422:in block (2 levels) in each_strongly_connected_component_from'
/opt/redmine/ruby/lib/ruby/2.3.0/tsort.rb:431:in each_strongly_connected_component_from' /opt/redmine/ruby/lib/ruby/2.3.0/tsort.rb:421:in block in each_strongly_connected_component_from'
/opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/railties-4.2.8/lib/rails/initializable.rb:44:in each' /opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/railties-4.2.8/lib/rails/initializable.rb:44:in tsort_each_child'
/opt/redmine/ruby/lib/ruby/2.3.0/tsort.rb:415:in call' /opt/redmine/ruby/lib/ruby/2.3.0/tsort.rb:415:in each_strongly_connected_component_from'
/opt/redmine/ruby/lib/ruby/2.3.0/tsort.rb:349:in block in each_strongly_connected_component' /opt/redmine/ruby/lib/ruby/2.3.0/tsort.rb:347:in each'
/opt/redmine/ruby/lib/ruby/2.3.0/tsort.rb:347:in call' /opt/redmine/ruby/lib/ruby/2.3.0/tsort.rb:347:in each_strongly_connected_component'
/opt/redmine/ruby/lib/ruby/2.3.0/tsort.rb:226:in tsort_each' /opt/redmine/ruby/lib/ruby/2.3.0/tsort.rb:205:in tsort_each'
/opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/railties-4.2.8/lib/rails/initializable.rb:54:in run_initializers' /opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/railties-4.2.8/lib/rails/application.rb:352:in initialize!'
/opt/redmine/apps/redmine/htdocs/config/environment.rb:14:in <top (required)>' /opt/redmine/apps/redmine/htdocs/config.ru:3:in require'
/opt/redmine/apps/redmine/htdocs/config.ru:3:in block in <main>' /opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/rack-1.6.8/lib/rack/builder.rb:55:in instance_eval'
/opt/redmine/apps/redmine/htdocs/vendor/bundle/ruby/2.3.0/gems/rack-1.6.8/lib/rack/builder.rb:55:in initialize' /opt/redmine/apps/redmine/htdocs/config.ru:1:in new'
/opt/redmine/apps/redmine/htdocs/config.ru:1:in <main>' /opt/redmine/ruby/lib/ruby/gems/2.3.0/gems/passenger-5.1.2/src/helper-scripts/rack-preloader.rb:110:in eval'
/opt/redmine/ruby/lib/ruby/gems/2.3.0/gems/passenger-5.1.2/src/helper-scripts/rack-preloader.rb:110:in preload_app' /opt/redmine/ruby/lib/ruby/gems/2.3.0/gems/passenger-5.1.2/src/helper-scripts/rack-preloader.rb:156:in module:App'
/opt/redmine/ruby/lib/ruby/gems/2.3.0/gems/passenger-5.1.2/src/helper-scripts/rack-preloader.rb:30:in <module:PhusionPassenger>' /opt/redmine/ruby/lib/ruby/gems/2.3.0/gems/passenger-5.1.2/src/helper-scripts/rack-preloader.rb:29:in <main>'