1) Start a mongod instance with dbpath: "E:\mongodb\data\db" and directoryperdb: true parameters. 2) Create a database "cacheagg", insert some data and stop instance 3) Rename folder "E:\mongodb\data\db\cacheagg" to "E:\mongodb\data\db\cacheagg_migrate" 3) Create a mounted folder on "E:\mongodb\data\db\cacheagg" 4) Move all files from "E:\mongodb\data\db\cacheagg_migrate" to "E:\mongodb\data\db\cacheagg" 5) Start instance and you review that everything is ok and then stop instance 6) Start repair process options: { auth: true, dbpath: "E:\mongodb\data\db", directoryperdb: true, keyFile: "C:\mongodb\bin\keyfilecacheagg.txt", logpath: "E:\mongodb\log\mongo.log", repair: true, repairpath: "E:\mongodb\data\db\mongodb_repair" }