I posted a question here because my HDDs keep spinning up for no apparent reason and wanted to find out what process causes them to spin up.
In the comments to that question, I was told to use
iosnoop which (without any arguments or switches) generated a few hundred lines within the few minutes it took one of the HDDs to randomly spin up. After copying the output and telling Emacs to remove all lines with the device number corresponding to the SD card (about accesses to which I don't care), I'm left with this:
COMM PID TYPE DEV BLOCK BYTES LATms dumpe2fs 19467 R 8,0 272648 4096 23.25 ^C Ending tracing...
As there only is 1 line of data left, it seems reasonable to assume that the culprit has been identified. But why is
dumpe2fs called randomly? More important than that: How do I make it stop, preferably without breaking stuff (which the dirty solution of renaming the corresponding file might do)?
sudo dumpe2fs /dev/sda1 manually does make the corresponding HDD spin up. The command, however, does already return its output and terminate before the HDD is spun up (without the ~ 7 s delay I experience when accessing files while the HDDs are spun down).
I use Ubuntu Mate 16.04.