Failed to create a transaction for the db: Permission denied
```
2019-04-14 05:55:08.912	    7f6c3ba71c00	WARNING	blockchain.db.lmdb	src/blockchain_db/lmdb/db_lmdb.cpp:75	Failed to create a transaction for the db: Permission denied
terminate called after throwing an instance of 'cryptonote::DB_ERROR_TXN_START'
  what():  Failed to create a transaction for the db: Permission denied

```