As a value investor , when do you sell?

I have been thinking about this lately.
In the books and articles of Value investing it is generally mentioned that the holding period of a stock for a value investor is eternity. We should only sell stock if business has some permanent flaws. And we should wait for compounding to take place.

However, I think that compounding doesn’t happen generally by staying in single stock for 4-5 years ( I mean upwards of 100% increase ).
What I think is that it is better to sell a stock which has raised 30% in 1-2 years and then find for other opportunity . In this way compounding seems logical.

I want your thoughts on how do you see this?