mongo compact all db and collection

compact.js

// rs.slaveOk(); 
db.getMongo().getDBNames().forEach(function(dbName) {
    if ("local" != dbName && "admin" != dbName && "system" != dbName) {
        var subject = db.getSiblingDB(dbName);
        subject.getCollectionNames().forEach(function (collectionName) {
            print('Compacting: ' +dbName + " - " + collectionName);
            subject.runCommand({ compact: collectionName });
        });
    }
});