On Manjaro KDE I've been using Dolphin for more than 3 years.
Only a few weeks ago it began to read my disks continuously,
all day, every day -- it never stops. It never did this before.
The version is 20.08.1

In system monitor, "IO Read" shows that each dolphin instance
is reading at a rate of a few hundred to a few thousand "K/s".
(Don't know whether "K/s" means bits or bytes.)

I have looked through the Dolphin settings, and it all looks normal.

Have instead tried PCManFM-Qt and SpaceFM in the last few days,
but find them too hard to work with, as they are missing some
of the functionality that Dolphin has.

For me, the file manager is at the centre of the PC universe
-- sometimes I have many windows open, with many tabs in each --
so I can't work without it, but can't bear to see the drive light
flickering all the time. (It stops when I stop all Dolphin instances.)

Manjaro has a Plasma update on the way, but I don't want
to just wait for it, in case it doesn't fix the problem.

Hope someone has a clue what might be causing this,
or can tell me exactly what info to get for a bug report.

Weird, I can't reproduce this here, version 20.08.2, and I don't recall this happening in the previous version. When idle the system load is at 0 CPU and barely some RAM
Do you have open tabs for many remote locations or NTFS shares?

Maybe saving and erasing the .config/dolphinrc file in your home folder helps?

Mamarok wrote:... I don't recall this happening in the previous version.

It started happening for me only a few weeks ago.

Mamarok wrote:Do you have open tabs for many remote locations or NTFS shares?

No, only internal disks.
And they have been the same for at least 2 years.

Mamarok wrote:Maybe saving and erasing the .config/dolphinrc file in your home folder helps?

No. (I saved the settings because I need them, but while they were gone, no difference.)

After moving dolphinrc out, when I opened only one Dolphin window,
and opened about 6 tabs in it, it did not happen.
When I opened a second Dolphin window and opened 2 tabs, it was still OK.
But after the 3rd tab opened, it kept on reading a disk (slowly) for hours.
The tabs in the 1st window showed both my drives,
so the 2nd window was not looking at something different.

Until a few weeks ago I could keep about a dozen windows open
with about a dozen tabs in each window, and after each tab had read
the necessary folders, Dolphin completely stopped reading disks.

Manjaro has Plasma 20.08.2 in testing; when it gets to stable I'll see if it helps.

Circular symlinks!

j77h wrote:The tabs in the 1st window showed both my drives,
so the 2nd window was not looking at something different.

Some of those tabs had opened automatically when I first opened Dolphin,
and the behaviour in that case was not the same as me opening them manually.

The continuous reading happens only after I have opened certain folders.
They are near the top of the tree, and most of my work is done below them.

There are some circular symlinks within that tree.
They connect folders that are in different branches of the tree,
but contain related material; they help me remember where things are.
There have been circular symlinks within that tree for years,
and they haven't caused a problem until now.

Recently the "save as" dialog in Firefox and SciTE does not show symlinks at all,
with the result that many of my usual folders are missing from the dialog.
EDIT: 'save as' in Kate is quite different, and my symlinks still work there,
so it looks like the problem is not in KDE.

It seems like, somewhere in the system, handling of symlinks changed a few weeks ago,
and this causes Dolphin to go into endless loops when it scans folders with symlinks to each other.

I suspect this is the reason, but don't know for sure, of course.
If it is the reason, I still have no idea which part of the system it's in (Kernel? X11?)
so don't know who to talk to ...

EDIT2: SpaceFM and PCManFM-Qt don't read the disk incessantly,
so to some extent it is a Dolphin problem.

j77h wrote:Circular symlinks!

'Circular' was the wrong word -- it means a link that points to itself.
I meant symlinks that cause endless loops, such as
folderA contains a link to folderB, and folderB contains a link to folderA.

Anyway, that's not the cause.
I removed the links and Dolphin still reads disks for ever.
(Replaced them with .desktop files with 'Type=Link'.)

No app would let itself get stuck in an endless loop anyway,
so this never would be the cause...

So why does Dolphin read disks for ever?
I think it started after the Plasma 20.08 upgrade.
What can i do to get the info needed for a bug report?

Did you try with a new user? There must be something in your settings causing it, I can't reproduce this.

In doubt, open a bug report, if there is additional information needed you will be asked for. Make sure to provide enough information on how to reproduce it, e.g. how many instances of Dolphin, how many tabs.

Mamarok wrote:I can't reproduce this.

Did you check by opening systemmonitor (System Activity),
and looking at the "IO Read" column?
The flickering of the disk light might not always be noticeable.
(It's not the light that bothers me, it's the constant disk access, for no apparent reason.)

e.g. how many instances of Dolphin, how many tabs

It can happen with 1 instance and 1 tab.
When I saw it not happen, I had opened a window but didn't use it.
Seems like it starts to happen as soon as I go looking in different folders.
Normally, there's a burst of disk read when I move to another folder, and then it stops.
The abnormal activity is that it doesn't stop, it only slows down.

Manjaro stable now has new Plasma and KDE Apps.
I'll install the update in a day or two.
If it still happens then, I'll make another user for testing.

Thanks.

Of course I have (how else would I monitor disk access...), and it simply doesn't happen.
Of course opening a new folder needs to read the disk, how else would it be able to display the content? But there is no continuous reading of the disk.

Just one little idea: do you have file preview activated? If this is the case, browsing e.g. a large picture folder with a lot of files might have to read longer to display the file preview, try disabling that and/or reduce the file types you have previews activated.

Mamarok wrote:Of course I have

OK, thanks. Just wanted to be sure.

do you have file preview activated?

No, I have always turned off that kind of thing.

AFAIK it started happening after a recent update,
and I hadn't changed any Dolphin settings, nor the way i use it.

Got Dolphin 20.12.0 in a Manjaro update today, and it's behaving fine now.
Guess it was a bug and they fixed it.

@Mamarok:
My disk has hundreds of thousands of files.
Maybe you couldn't reproduce the behavior because you didn't have so many files ...

j77h wrote:@Mamarok:
My disk has hundreds of thousands of files.
Maybe you couldn't reproduce the behavior because you didn't have so many files ...

You have no idea....