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TL;DR Is there a way under Linux to know which file access caused an hard disk to spin up?
Full story My laptop has a NVME disk, which contains the operating system and my home dir, and a spinning hard disk, which contains a second home dir which I use to store bulk data that do not fit on the NVME. I believe it is a common arrangement.
One of the nice things is this layout is that when I am not working on the projects that require files on the spinning disk, the disk itself can spin down, saving on energy, battery time, noise, etc. And this happens quite frequently.
However, every now and then the hard disk spins up even if what I am doing in that moment has no clear link with data that are stored there. It is still a consequence of an action done by me, not of a cron script or something else, because it still happens as a consequence of my doing something, like opening an application. However I cannot see what opening that application should produce an access to the spinning disk, knowing which file are supposed to be there. So I would like to understand more of what happens, and this justifies the question above.