Currently we are running Cloudera manager without HA capability.
what pre-cautionary measures that can we take now , which would help us in re-building the environment in-case of hardware failure ?
All of Cloudera Manager's information is stored in the CM database. There are some other minor things, but here are the primary things to back up regularly to ensure you can revert to a recent state in case the CM host breaks:
The main thing is the db backup.
That should be a start.