If you want to use the DISC cluster, you have to set your default shell to bash. There is a lot of shell support for hadoop and it all comes from the factory in bash. For this reason we only support bash on the DISC cluster. Note: running "bash -l" when log in isn't sufficient. You don't get an opportunity to say "bash -l" when the session is non-interactive, like when you need to copy a large file directly into HDFS via ssh, for example.
You can change your shell back to bash here:
https://alpha.pdl.cmu.edu/~account/cgi-bin/chpwBack to:CloudClusterFAQ