我正在使用EC2(适用于Ubuntu 16.04(，并且安装了mongodb 3.6 但是当我使用以下命令启动它时
mongod --port 27017 --dbpath /data/db
它给出以下错误
An unsupported journal format detected - If you are trying to rollback from version 4.0 to 3.6, please re-start a 4.0 binary and cleanly shut it down so that the journal format will be downgraded.
Assertion: 28595:13: Permission denied src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.cpp 488
exception in initAndListen: Location28595: 13: Permission denied, terminating
Invariant failure globalStorageEngine src/mongo/db/service_context_d.cpp 272
请建议
尝试：
sudo service mongod restart
sudo service mongod status
sudo service mongod stop
sudo service mongod status
然后也许你的命令要遵循