Tvheadend

Hello,

I am having troubles understanding these features.

1- In dvr log retention period, I can set 'forever' however I do not understand this. If I delete the entry from recordings section of tvheadend, does this mean that log stays? How do I access it then? or what is the purpose?

2- In dvr log retention period, I can set 'on file removal'. Is this in case if remove the file manually outside tvheadend? But does tvheadend check existence of every file regularly?

3- If I set file removal to 1 day but log removal to forever, does the logs stay forever? how do I access the logs after tvheadend remoevs files in that case?

Thanks!