質問: Logger.new('log/development.log', 10, 1 * 1024 * 1024) ■エラー内容(development.logの内容) I, [2016-07-12T19:58:33.823987 #3345] INFO -- : Rendered layouts/xxx.html.erb (14.7ms) log shifting failed. closed stream log writing failed. closed stream I, [2016-07-12T19:58:33.827129 #3345] INFO -- : Completed 200 OK in 1269ms (Views: 1000.2ms | ActiveRecord: 259.9ms) log shifting failed. closed stream log writing failed. closed stream
回答: Nginx+UnicornのProduction環境では正しくローテートされましたので質問を取り下げます。