Nepomuk and strigi worked just fine before I updated Kubuntu 10.04 to KDE 4.4.4 via backports. Now after a few minutes of logging in, all metadata I added via nepomuk (tags, comments, etc.) disappears, and even the list of available tags is either empty or replaced with ones of the form nepomuk://... (or something like this---I don't have them anymore for the reason below).

I used to also get strigi results for indexed pdfs. Now I always get a return of "No items found" in dolphin. So I deleted my ~/.kde/share/apps/nepomuk/repository/main/data/sesame2 and ~/.kde/share/apps/nepomuk/repository/main/data/redland folders (since I figured they're not needed now that nepomuk is using the virtuoso backend) and the entire contents of ~/.kde/share/apps/nepomuk/repository/main/data/virtuosobackend. I started reindexing everything (there now exists a 70MB database file) but I still get "No items found" when I search for anything.

So obviously Nepomuk CAN be made to work but that people who are doing Ubuntu's backport packaging have a tendency to break stuff. Can it be fixed? For the time being I've had to disable nepomuk because it's utterly useless.

When you removed the Nepomuk databases were you logged into KDE? If you were, please try logging out, removing them, and logging back in again.

I stopped nepomuk, deleted the entire nepomuk folder, restarted the computer, and then restarted nepomuk but did not log out and in again. Tagging files gave me weird tags of the form "nepomuk:/res...". I logged out and back in and everything's working fine now. I should try restarting the computer again to see if this working state sticks.

The developers should implement some sort of WARNING that logging out and in may be (or IS) required for things to work after restarting nepomuk. There really is just no way to tell.

And upon reboot metadata is lost again! This is clear indication that one ought not bother using nepomuk, at least one ought not feel confident in retaining her data.

Can you please try stopping Nepomuk Server ( killall -2 nepomukserver ) then starting Nepomuk Server manually? ( nepomukserver & )

Not sure if this is a fault in KDE or in distribution packaging, however Nepomuk and Akonadi start without issue here on trunk ( as Plasma's clock now interfaces with Akonadi to show appointments, causing it to automatically start and Akonadi shows error messages if Nepomuk isn't available )

I tried stopping and restarting nepomuk server manually to no avail. There is a window between logging in with a working nepomuk/strigi and then it not working. I'll see if it's caused by my starting certain applications such as Kopete.