How to Use Time Machine on the same HD than the System

If you create 2 partitions on the same HD, you can use the first one for the system and storage, and configure the second one for Time Machine. When selecting the second partition, you will be warned that this solution is not reliable, as you will lose all data in case of HD failure.
However this solution might also be useful if you simply need to recover previous versions of files or files involuntary deleted.
However, you should keep in mind the following points:
- as you will lose all data in case of HD failure, pay attention to perform regular backup of this HD
- backups performed by Time Machine will place heavy request on HD heads, and could lead to a shorter life cycle.
- also due to those reading/writing cycles, the computer reactivity will massively decrease when Time Machine will be running, so it might useful to only perform such backup every 12 hours instead of the default 1 hour with applications such as TimeMachineScheduler.