backup and compacting files in influxdb

_Describe the issue here._

##### Relevant URLs
- https://docs.influxdata.com/influxdb/v1.8/administration/backup_and_restore/
- _Provide other relevant URLs (project issues, community threads, etc.)_
/////////////////////////////////////////////////////////////////////////////////////////////
Hi
To whom it's important to;

I have some questions in Influxdb v 1.8 and I hope you guys help me a little, and I don't know if these are bugs or not.

First question:
how to stop influxd process?

In the documentation in Compact a series file offline first step is stopping influxd process.

Second question:
Is there any ways to restore compact data to normal type?
if the answer is yes, HOW?

Third question:
How does compacting work for decreasing file size on disk when we remove the normal data from the autogen directory ?

Fourth question:

Is there a way for restoring deleted compacted files?
If the answer is yes, HOW?

Thank you all for help.
I have searched for a long time like a month, but I steel couldn't find the answers.

Start with the linked InfluxDB 1.8 backup and restore documentation and its section on offline series-file compaction. Determine how stopping influxd, restoring compacted data, reclaiming space, and recovering deleted compacted files are documented; done means the relevant documentation clearly answers these four questions or states the supported limitations.

Written by the indexing model from the issue text.