Samba SMB Disk Activity

[wk170]

During the day, sometimes the HDDs in my NAS start making a lot of noise/activity, while no users are active or jobs running.

Have disabled most of the services running and including Qsync, Multimedia-services, etc
So most of the day you do not hear any disk activity, but suddenly they start making a lot of noise/activity, which goes on for a couple of minutes.

Have installed IOtop, and captured the screenshot while it was happening.

Anyone an idea what is going on?
Is it perhaps related to the Samba cache or so?

IOtop.png

[wk170]

Did some more investigation, and found out that the extreme disk activity always immediately happens when I write my first file from my Windows 10 computer to my QNAP, directly after I have booted my QNAP
After that it does not happen anymore, only once again after I have booted my QNAP.
So it is always once after a QNAP boot, and during the first file written from Windows to QNAP.
Have a TS-453A QNAP running 4.5.3.1652 Build 20210428

During that extreme disk activity, that goes on for minutes, during which all disk operations are stalled, IOtop shows that the following command is running: smbd -l /var/log -D -s /etc/config/smb.conf

Also, that first file that I copied, is initially created on my QNAP as Size:0 and Size on disk 4,31GB. <<Size 0
Once the disk activity is resumed, and the extreme disk activity has ended, I get a Windows prompt if I want to replace the file, because it already exists.

Any ideas what is going on, and how to fix it?

[lmarceg]

Hi,
I have started to see the very same issue of high disk activity from samba (I have installed iotop as well to monitor it). In my case, this happens twice or three times a day, without me rebooting anything. The smbd is launched by luca, which is the SMB user connected to Win10 (the Mac uses NFS). I have a very huge disk activity, as you can see from the screenshot.

Screenshot 2022-01-13 at 00.46.32.png

It looks like it's mainly reading data, as actually the log file is basically empty.
And I don't know how to solve it
Luca