Failed to add the host to the list of known hosts, how to debug [closed]

Question

Try to ssh using -v. The output is:

ccc@es-chen:~$ ssh cccadmin@ccchost -A -X -v
OpenSSH_5.9p1 Debian-5ubuntu1.7, OpenSSL 1.0.1 14 Mar 2012
debug1: Reading configuration data /home/ccc/.ssh/config
debug1: /home/ccc/.ssh/config line 11: Applying options for *
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to ccchost [10.36.64.12] port 22.
debug1: Connection established.
debug1: identity file /home/ccc/.ssh/id_rsa type 1
debug1: Checking blacklist file /usr/share/ssh/blacklist.RSA-2048
debug1: Checking blacklist file /etc/ssh/blacklist.RSA-2048
debug1: identity file /home/ccc/.ssh/id_rsa-cert type -1
debug1: identity file /home/ccc/.ssh/id_dsa type -1
debug1: identity file /home/ccc/.ssh/id_dsa-cert type -1
debug1: identity file /home/ccc/.ssh/id_ecdsa type -1
debug1: identity file /home/ccc/.ssh/id_ecdsa-cert type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.9p1 Debian-5ubuntu1
debug1: match: OpenSSH_5.9p1 Debian-5ubuntu1 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.9p1 Debian-5ubuntu1.7
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5 none
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: sending SSH2_MSG_KEX_ECDH_INIT
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ECDSA 17:d5:07:c8:1f:80:2d:5a:95:9b:95:ce:31:de:54:5e
The authenticity of host 'ccchost (10.36.64.12)' can't be established.
ECDSA key fingerprint is 17:d5:07:c8:1f:80:2d:5a:95:9b:95:ce:31:de:54:5e.
Are you sure you want to continue connecting (yes/no)? yes
Failed to add the host to the list of known hosts (/home/ccc/.ssh/known_hosts).
debug1: ssh_ecdsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,password
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /home/ccc/.ssh/id_rsa
debug1: Authentications that can continue: publickey,password
debug1: Trying private key: /home/ccc/.ssh/id_dsa
debug1: Trying private key: /home/ccc/.ssh/id_ecdsa
debug1: Next authentication method: password
cccadmin@ccchost's password: 
debug1: Authentications that can continue: publickey,password
Permission denied, please try again.
cccadmin@ccchost's password: 
debug1: Authentications that can continue: publickey,password
Permission denied, please try again.
cccadmin@ccchost's password: 
debug1: Authentications that can continue: publickey,password
debug1: No more authentication methods to try.
Permission denied (publickey,password).

How to figure out why? Any ideas? thanks

Answer 1

I did not have the permission for some ssh related files.

ls -al /home/ccc/.ssh/known_hosts
-rw------- 1 root root 7770 Jan 20 16:14 /home/ccc/.ssh/known_hosts

Get permission:

ccc@es-chen:~$ sudo chown -R ccc:ccc .ssh
ccc@es-chen:~$ ssh cccadmin@ccchost -A -X 
The authenticity of host 'ccchost (myip)' can't be established.
ECDSA key fingerprint is 17:d5:07:c8...............:54:5e.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'ccchost,myip' (ECDSA) to the list of known host

OK now