Unable to ssh into logger

* Deploying via : AWS

### Description of the issue:
The main issue is I'm seeing this error on my splunk after running few tests:
`The minimum free disk space (5000MB) reached for /opt/splunk/var/run/splunk/dispatch`

###Sub issue
In order to fix this I need to SSH into my logger. I'm using the id_logger keys created during the deployment. When I login using this keypair to the logger, it is asking me for username and password. I did not set any password when creating this key pair. I tried few passwords like vagrant,changeme etc but not working.

### Question
Please let me know how can I ssh into my logger using id_logger key pair.