Not sure how to keep history from being lost

[JStateson]

I thought if I set "remove history after 2 days" and also "move to long term storage after 2 days" that I could save history files that have older data and would get (3*long) *2 days + 1 cvs worth of old and fresh data (7 days).  That didn't happened as it is not working like I guessed.

Looking at the help info here I see the recommended is after 7 days.  The files at \appdata\roaming\efmer\BoincTasks\history that are named "long" never seem to have anything in them other than headers.

With 2 and 7 days respectively it seems like I would lose 5 days of data after the 7th day but that does not happen as nothing gets into the "long" files.

I get cvs1 & cvs2 filling even though I have not checked "Make  a  backup ..... (not recommended)".

I did not see an explanation for that option.   Why is it not recommended?

Asking about this as my app "BTHistoryReader" is more useful if there is more data to analyze and I am losing data after 2 days and would like to have at least a weeks worth of data to analyze.

[fred]

Ok what happens.
Before the history file is written what happens cvs -> cvs1 cvs1 -> cvs2 in effect this is only a rename sequence.
The actual history file is now cvs with cvs1 and cvs2 as a backup copy.
In the event something happens, like the computer shuts down while writing the history file, cvs may be corrupt and the cvs1 is used instead as the latest valid history file.

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Remove history after xxx does just that, it removes all entries in both the history and long term history that are older than the set days.
So if you set both remove and move to long term history at 2 days, long term history stays empty as it is set to delete before it gets moved, or gets deleted just after being moved.

Set Move to long term history after 2 days.
Set Remove history after 30 days.
Everything older than 30 days gets deleted, in this case only from long term history, if there is anything yet.
Now you get 2 days in history and 28 days in long term history.

Any change you make in the settings might not happen all at once.
If you change remove after from 30 -> 20 it will gradually remove all older entries, this may take hours if there are a lot. This keeps BoincTasks from deleting hundreds of files all at once and overloading BT or the system.
The same thing if you make changes in move to long term history after, it may take a while.

The backup checkbox makes another backup set and is a left over.

[JStateson]

Thanks Fred!

I will include the setup part about 2 days and 30 days in my app.