$ mongo mono -u admin_all -p 1234 MongoDB shell version: 2.4.6 connecting to: mono > db.system.users.find() { "_id" : ObjectId("52a9831de41eb640bb0f5f64"), "user" : "admin_all", "pwd" : "a6316ed4886c10663cce46bc216ea375", "roles" : [ "userAdmin", "userAdminAnyDatabase" ] } { "_id" : ObjectId("52a98404ef1f9bc934b62e11"), "user" : "admin_one", "pwd" : "884f516cf308a4c6a75bbc5a0a00807b", "roles" : [ "userAdmin" ] } { "_id" : ObjectId("52a98415ef1f9bc934b62e12"), "user" : "admin_any", "pwd" : "1616611df9b47c58b607054d384cab99", "roles" : [ "userAdminAnyDatabase" ] } > use another switched to db another > db.addUser( { user: "user", pwd: "1234", roles: ["read"] } ) { "user" : "user", "pwd" : "461d4f349d8d4ec3d22a4c945010c330", "roles" : [ "read" ], "_id" : ObjectId("52a985372fcdbfd033003a7e") } Thu Dec 12 10:43:19.091 couldn't add user: not authorized for insert on another.system.users at src/mongo/shell/db.js:128 >