結論から言うと、私は月間約 25 万ビューの中規模 Discourse サイトの運営を手伝っています。サーバーの帯域幅やストレージスペースを節約するために、バックアップとアップロード先を S3 に切り替えました。しかし、現在ローカルに保存されている約 6GB のアップロードデータも S3 バケットへ移行したいと考えています。こちらのガイドやサポート資料を参照して rake uploads:migrate_to_s3 を実行しようとしたのですが、エラーが発生して失敗しています。
現在は Digital Ocean の VPS でホストしています。
私の現在の状況と非常に似ている以下のトピックを見つけました。
launcher を使ってアプリにログインした後、実行したコマンド（一部匿名化済み）のログは以下の通りです。
root@discourse-s-2vcpu-4gb-nyc1-01-app:/var/www/discourse# DISCOURSE_S3_BUCKET=insert_bucket_here DISCOURSE_S3_REGION=us-east-2 DISCOURSE_S3_ACCESS_KEY_ID=AMAZON_SECRET_HERE DISCOURSE_S3_SECRET_ACCESS_KEY=SECRET_KEY_HERE rake uploads:migrate_to_s3 --trace
** Invoke uploads:migrate_to_s3 (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute uploads:migrate_to_s3
Migrating uploads to S3 for 'default'...
Some uploads were not migrated to the new scheme. Running the migration, this may take a while...
rake aborted!
FileStore::ToS3MigrationError: Some uploads could not be migrated to the new scheme. You need to fix this manually.
/var/www/discourse/lib/file_store/to_s3_migration.rb:155:in `migrate_to_s3'
/var/www/discourse/lib/file_store/to_s3_migration.rb:65:in `migrate'
/var/www/discourse/lib/tasks/uploads.rake:239:in `migrate_to_s3'
/var/www/discourse/lib/tasks/uploads.rake:218:in `block in migrate_to_s3_all_sites'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rails_multisite-2.1.2/lib/rails_multisite/connection_management.rb:64:in `with_connection'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rails_multisite-2.1.2/lib/rails_multisite/connection_management.rb:74:in `each_connection'
/var/www/discourse/lib/tasks/uploads.rake:216:in `migrate_to_s3_all_sites'
/var/www/discourse/lib/tasks/uploads.rake:212:in `block in <top (required)>'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rake-13.0.1/lib/rake/task.rb:281:in `block in execute'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rake-13.0.1/lib/rake/task.rb:281:in `each'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rake-13.0.1/lib/rake/task.rb:281:in `execute'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rake-13.0.1/lib/rake/task.rb:219:in `block in invoke_with_call_chain'
/usr/local/lib/ruby/2.6.0/monitor.rb:235:in `mon_synchronize'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rake-13.0.1/lib/rake/task.rb:199:in `invoke_with_call_chain'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rake-13.0.1/lib/rake/task.rb:188:in `invoke'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:160:in `invoke_task'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:116:in `block (2 levels) in top_level'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:116:in `each'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:116:in `block in top_level'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:125:in `run_with_threads'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:110:in `top_level'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:83:in `block in run'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:186:in `standard_exception_handling'
/var/www/discourse/vendor/bundle/ruby/2.6.0/gems/rake-13.0.1/lib/rake/application.rb:80:in `run'
bin/rake:13:in `<top (required)>'
/usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/lib/bundler/cli/exec.rb:63:in `load'
/usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/lib/bundler/cli/exec.rb:63:in `kernel_load'
/usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/lib/bundler/cli/exec.rb:28:in `run'
/usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/lib/bundler/cli.rb:476:in `exec'
/usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/lib/bundler/cli.rb:24:in `start'
/usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/exe/bundle:46:in `block in <top (required)>'
/usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/lib/bundler/friendly_errors.rb:123:in `with_friendly_errors'
/usr/local/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/exe/bundle:34:in `<top (required)>'
/usr/local/bin/bundle:23:in `load'
/usr/local/bin/bundle:23:in `<main>'
Tasks: TOP => uploads:migrate_to_s3