We completely make main plane and backup machine agree.
When backup is carried out, deletion or added file deletes with backup machine or we are added.
- When backup is carried out, main plane and backup machine become the same state, and restoration is easy.
- Other synchronization has less backup capacity than type and finish.
- We cannot take they data with backup machine after backup was carried out after putting out with main machine by mistake, and having overwritten.
Main plane data
Backup machine data
We can take out at the time of the fourth