RN104 disks (semi)randomly spinning up

Hi there,

My RN104 disks (4x 3TB disk, RAID5) seem to randomly spin up multiple times a day and since I don't even access the NAS daily, I feel like this is a bit of a waste. Example: I accessed the NAS about 27 hours ago, turned off the computer and went to bed ~3h later, around 00:30, and was away all day. Today from 00:00 till 21:00 the disks/a disk spun up 12(!) times.

It seems like the cron.hourly ran by user:root might have something to do with it, e.g.:

From system.log:
Jul 20 00:17:02 G-NAS CRON[1864]: pam_unix(cron:session): session opened for user root by (uid=0)
Jul 20 00:17:02 G-NAS CRON[1865]: (root) CMD (   cd / && run-parts --report /etc/cron.hourly)
Jul 20 00:17:14 G-NAS CRON[1864]: pam_unix(cron:session): session closed for user root
and from spindown.log:
Jul 20 00:17:17 G-NAS noflushd[1188]: Spinning up disk [#1-4]

But often the disks don't spin up at these cron sessions and sometimes the disks spinup without a system or cron entry.

Can anyone confirm it's these cron.hourly jobs or find out what else is causing these spinups. I've got the zip with logs ready, if they're needed. Is there any way to make these spinups less frequent, maybe by disabling/deleting the cron.hourly tasks.

I've connected through ssh with PuTTY, though not as user root, but I've no idea where to start anyway. I've never really used SSH/PuTTY before, but I am a fairly advanced pc/Windows user, so you don't have to be gentle with me ;)

Thanks for any help in advance!

Also (maybe/probably unrelated), just wondering about this:

system log:
Jul 20 02:44:20 G-NAS smbd[1360]: pam_unix(samba:session): session closed for user guest
spindown log:
Jul 20 02:44:22 G-NAS noflushd[1188]: Spinning up disk [#1-4]

Why does a guest session closing spin up the disks? And why is there no mention of a guest session opening ever? Is this anything to worry about?