I mean the one it does every time it starts, when it looks if everything is where it thinks it is. At least when I start it the progress bars are white and the status says checking or something similar, it takes maybe 4-5 seconds.
I don't seed 24/7, I shut down the PC most of the time, and I don't have all the HDDs on auto mount, I have remember to mount them before starting qbittorrent or it wont find half of the files.