I am not sure if this is the right place to ask for a solution -- if not, please tell me where to ask.

After installig Debian11 BalooSearch is not running, however, there are no problems under the old system (Debian Buster). Did I miss to activate something or to configure Dolphin properly?

These are a few of the things I did:
-- all relevant packages are installed
-- configured balooctl via Konsole:
there is no stop option anymore and balooctl purge does not work, otherwise everything seems fine
-- increased inotify watchers permanently to 1048576 as prior number might have been too low
-- DISABLED File Search in System Settings (which is very counterintuitive!!!), otherwise it would have done nothing

Persistent problems:
1. if searching in Dolphin (Version 18.08.0) under the old system, the tab switched to "baloosearch", now (Dolphin v.20.12.2) it just says "Search for ..."; hence Baloo might not even be running
2. under the old system (Baloo 5.54.0) search options were "From Here" and "Everywhere", and via the last all folders specified under "balooctl config list includeFolders" could be searched; now there is no "Everywhere" anymore but a "Your Files", which is just the home directory, and "From Here", once used, always falls back also to the home directory
3. Baloo File Indexer says it is running, but does not much; total files indexed are equivalent to the number in the old system, but the index size is less than 1/10 of the old size; this would not be a problem if baloo would find the things searched for; balooctl disable followed by balooctl enable in Konsole would normally trigger the creating of a new index, however, nothing happens

Questions:
What do I have to do to use again Baloo within Dolphin?

Thanks for your help,
bbk

After installing Debian11 BalooSearch is not running, however, there are no problems under the old system (Debian Buster).

A fresh install or an upgrade? If you are upgrading from Debian 10 to 11 you could run into Bug #431664 and see the effects of earlier index corruption.

.... there is no stop option anymore and balooctl purge does not work, otherwise everything seems fine

It could be that "balooctl suspend" (that "pauses" the indexing) or "balooctl disable" (that closes down baloo and leaves it disabled) will do what you are expecting "stop" to do.

If you say "balooctl purge" does not work, you mean it does not close down the baloo_file/baloo_file_extractor processes and delete the

.local/share/baloo/index

file? If baloo gets stuck indexing a very large file, it does not always respond to a "balooctl disable" or "balooctl purge". These send requests to baloo to stop and go away, except it can be indexing and not listening. You might need to do a "pkill baloo_file" and then the "balooctl purge".

1. if searching in Dolphin (Version 18.08.0) under the old system, the tab switched to "baloosearch", now (Dolphin v.20.12.2) it just says "Search for ..."; hence Baloo might not even be running

You can watch the indexing "as it happens" by running "balooctl monitor", if you create/edit files you should see baloo_file notice and queue them for content indexing (assuming you are doing content indexing)

Dolphin knows if you've configured baloo index only "some" directories. If you go to one of these directories and search, dolphin will ask baloo. If you are _not_ in an indexed directory, dolphin will do a "there and then" search (and you might need patience as it can be quite a bit slower)

2. under the old system (Baloo 5.54.0) search options were "From Here" and "Everywhere", and via the last all folders specified under "balooctl config list includeFolders" could be searched; now there is no "Everywhere" anymore but a "Your Files", which is just the home directory, and "From Here", once used, always falls back also to the home directory

I would expect "Your Files" to be the same as older "Everywhere". There does seem to be something confusing here though...

3. Baloo File Indexer says it is running, but does not much; total files indexed are equivalent to the number in the old system, but the index size is less than 1/10 of the old size; this would not be a problem if baloo would find the things searched for; balooctl disable followed by balooctl enable in Konsole would normally trigger the creating of a new index, however, nothing happens

With 5.78 you need to "balooctl purge" to clear the old index and start again. Watch out for "balooctl enable", it can be that you might need to invoke it twice to get the indexing to start.

To check whether baloo has indexed something, you can try

$ balooshow -x one-of-your-files

To query the index directly (instead of searching in Dolphin), try:

$ baloosearch one-of-your-files

Thank you for your profound answer and sorry for not replying earlier, but as there was no answer for 2 weeks, I did not expect any response anymore. In any case, I just solved the problem going through your post.

Regarding your questions:

nuxwoxaflyh wrote:A fresh install or an upgrade?

It's a totally fresh install.

It could be that "balooctl suspend" (that "pauses" the indexing) or "balooctl disable" (that closes down baloo and leaves it disabled) will do what you are expecting "stop" to do.

"balooctl stop" was a valid command in Baloo v.5.54 but it does not work anymore in v.5.78. As I did not use it often anyway, nothing is missing here.

Dolphin knows if you've configured baloo index only "some" directories. If you go to one of these directories and search, dolphin will ask baloo. If you are _not_ in an indexed directory, dolphin will do a "there and then" search (and you might need patience as it can be quite a bit slower)

THANKS, THIS ANSWER put me on the right track. Apparently, Baloo was already running in the background all the time. However, the tab header showed only "Search for PATTERN" instead of the "baloosearch" in the old version, and it also did not find anything (despite indexing was finished). Hence, I was not aware that baloo was doing anything.
As there is no "Everywhere" search options anymore, I started at "From Here (/)" and, thus, it also looked into a lot of non-indexed directories, which kept it running without showing results.

I would expect "Your Files" to be the same as older "Everywhere". There does seem to be something confusing here though...

Unfortunately, "Your Files" looks only into the home directory. Using "From Here (/)" is no help as it can run for hours. The older "Everywhere" option is missed desperately.

With 5.78 you need to "balooctl purge" to clear the old index and start again

Thanks, good to know!
bbk