Why server keeps access the disk containing the "seafile-data" folder, even no storage data exchanged

in my home server, the seafile dir is stored in the ssd, while the seafile-data is separated and put in the hdd.
the plan is, if there is no “real” data exchange related with seafile-data, then the hdd is not bothered at all, and after some long enough “timeout” (already set as 30min), the hdd could spin down and stay until a “real” data exchange occurs.

but it does not work, seafile server will spin up the hdd within one minute.
(after systemctl stop seafile the hdd finally could be able to stay in spin-down mode)

does seafile server keeps access the disk which contains seafile-data unconditionally?
actually i already used fatrace to monitor the file system activities, but didn’t find any related trace in the results. (i might missed something i’m not sure)
is there anything else to try out? or is my goal simply impossible?