Error when initiating replica set with some old data in local database:

rs.initiate() 
{
"errmsg" : "local.oplog.rs is not empty on the initiating member. cannot initiate.",
"ok" : 0
}

Solution:

use local

db.oplog.rs.drop()

 

 

Error when initiate replicaset in MongoDB:

“errmsg” : “replSet error loading set config (BADCONFIG)”, “ok” : 0 }

Solution:

1. Stop mongod, delete all local.* files in DBPath, start mongod or delete database local directly in mongo shell:

use local
db.dropDatabase()

2. Reconfigure replica set members:

config = {_id: “repl1″, members:[

{_id: 0, host: ‘192.168.2.1:27017′},

{_id: 1, host: ‘192.168.2.2:27017′}]

}

 

rs.reconfig(config, {force: true})