first, FQDN is a mandatory for Hadoop functionality.
If you are unable to setup real DNS, please use your /etc/hosts file(s).
You should not have more than 1 127.0.0.1 lines in /etc/hosts.
Give some "real" ip to your box and edit your /etc/hosts file to be something like:
127.0.0.1 localhost.localdomain localhost
put same name (jjscentos64) to /etc/sysconfig/network
this way your FQDN will be jjscentos64 and this will work fine.
As of pdsh update, why do you want to use it? Please do not update anything.
Just ignore all updates and restart HMC after you make changes in /etc/hosts