使用kerberos的hadoop集群，如果在kerberos配置文件正确，但访问hdfs报错：
WARN ipc.Client: Exception encountered while connecting to the server : javax.security.sasl.SaslException: GSS initiate failed [Caused by GSSException: No valid credentials provided (Mechanism level: Failed to find any Kerberos tgt)] Bad connection to FS. command aborted. exception: Call to localhost/127.0.0.1:8020 failed on local exception: java.io.IOException: javax.security.sasl.SaslException: GSS initiate failed [Caused by GSSException: No valid credentials provided (Mechanism level: Failed to find any Kerberos tgt)]
那就看看你的java版本，是否大于等于jdk 6 update 26。
换成jdk 6 25的就能解决。