Constant HDD read activity according only to KDE System Monitor widget?

Ask Fedora
1

Hello! I’m baffled by what seems to be a contradiction in my System Monitor. This is a recurring ‘problem’ (if it’s actually a problem) but it seems to happen randomly and restarting it resolves it.

I have the Hard Disk Activity widget on my desktop, and on random days it starts showing nonstop read activity but I can’t figure out why. A few days ago it was a permanent ~150mib/s. It just started again today and its a constant ~90/mibs. If I open System Monitor itself, it shows no read activity, neither does running $ sudo iotop -o. There’s also no corresponding network usage.

Screenshot here.

For some context, I have two HDDs in a RAID 1 (DH Raid) and one SSD (fedora), plus two other SSDs for other operating systems. I went ahead and added a second widget with every read activity for every drive in my computer, and it seems to be coming from one of my two hard drives that are in the RAID 1. Not the RAID itself as mounted, and not from both hard drives in the RAID, but just one of the two.

Any idea how I can track down this phantom read activity, or confirm if this is just some bug in the widget? Am on Fedora KDE 44 with KDE Plasma 6.7.3.

2

My guess is that it could be that it is the system indexing file for searching.
Next time this happens look to see what the apps are busy with top.

I think the tool used on KDE is baloo. Do you see baloo_file running?

3

I see baloo_file running under processes in System Monitor with 2.3mb memory but no read/write activity. $ top shows a bunch of process running (kwin_wayland, plasmashell, zen, md0_resync (md0 being my RAID), etc. but no mention of baloo_file there.

Would system indexing only happen on one of my two RAID drives? I might be very misinformed, but that’s the most confusing part for me, personally.

4

Run iostat -zx 1 and compare with your monitor widget. That will show you what device is actually performing the io.

You can then use iotop to see which service is actually reading or writing. Might be easier jsut to go straight to iotop thinking about it.

5

This looks like typical RAID behavior. They periodically index/synch. I see that on my NAS all the time.