Thursday, February 11, 2010

Kubuntu Karmic, KDE 4.4 and Nepomuk

Wow, long time no see. Haven't blogged in a while.

Firstly, let me just say that I'm so proud of everyone involved with KDE, SC 4.4 is a brilliant release!

Now, down to some nitty-gritty.

I'm using the great karmic-backports PPA to get my fresh copy of KDE 4.4 as I'm sure others are too. One problem I came across was that Nepomuk, Akonadi and Virtuoso didn't seem to be playing nicely and as a result I wasn't able to use these great technologies to their fullest. Basically, I was getting the 'Nepomuk not running' error popping up. This was because Virtuoso was reporting a pre-6.0 DB and refused to deal with it (old virtuoso 5x DB from previous upgrades through karmic-backports PPA). Unfortunately, virtuosoconverter didn't work and reported that it couldn't see a legit Virtuoso installation.


#> akonadictl stop
#> qdbus org.kde.NepomukServer /nepomukserver quit
#> kbuildsycoca4 --noincremental
#> rm ~/.kde/share/apps/nepomuk/repository/main/data/virtuosobackend/*
#> nepomukservicestub nepomukstorage
#> akonadictl start

That fixed it for me, hope this helps anyone else with the same issues.

Now I can go back to thoroughly enjoying this great release! I'll be sure to blog more about my experiences in the future.


  1. Knowledge gathering =)
    anyway, a short answer is very welcome.
    It solves the problem in other distros too.

  2. As mentioned in release announcement, virtuosoconverter packages should be used to convert your Virtuoso 5.x database to 6.x format.

  3. I don't understand why I have to build and install redland, rasqal, raptor, oscaf, iodbc, virtuoso, etc. if I don't even know what the hell is a semantic desktop, the first thing I do anyways is disable nepomuk.
    What a waste of brainpower and cpu cycles is going into KDE4.

  4. @Lure

    As mentioned in the article, virtuosoconverter didn't work - nor did Sebastien plan for virtuosoconverter to be a mass market solution to db conversion.


    The only thing you need is virtuoso, redland isn't used any more.

    For a description of the semantic desktop, read this:

    The semantic desktop is a great evolution in computing and I really look forward to greater integration of this technology into KDE's software.

  5. When I run nepomukservicestub nepomukstorage, I am getting stuck on
    "/usr/bin/nepomukservicestub(17956)" Error in thread 3045906272 : "storage: BDB V4.1+ open of '/home/arthur/.kde/share/apps/nepomuk/repository/main/data/redland/soprano-sp2o.db' failed - No such file or directory (error)"
    (Soprano::Redland) "storage: BDB V4.1+ open of '/home/arthur/.kde/share/apps/nepomuk/repository/main/data/redland/soprano-sp2o.db' failed - No such file or directory (error)"
    "/usr/bin/nepomukservicestub(17956)" Error in thread 3045906272 : "storage: BDB V4.1+ open of '/home/arthur/.kde/share/apps/nepomuk/repository/main/data/redland/soprano-sp2o.db' failed - No such file or directory (error)"
    nepomukstorage(17956) Nepomuk::Repository::open: Unable to convert old model: cound not load old backend "redland"
    nepomukstorage(17956)/nepomuk (storage service) Nepomuk::Storage::slotNepomukCoreInitialized: Failed to initialize nepomuk core

    You mention that redland isn't in use anymore. Any ideas?

  6. @Socceroos:

    You say the only thing I need is virtuoso? Thats not true.
    kde requires soprano, which requires redland, which requires rasqal, which requires raptor.

    soprano CAN be built without redland, and you can build kdelibs, kdepimlibs with this soprano, but then you won't be able to build kdepim. And if this is not painfully enough, soprano has problems with some versions of redland, but you won't know this until you already made your way through building several other packages.

    We have to go through all this crap even though most people will disable nepomuk anyways. So why not make it optional?

  7. @John

    True, you do need those extra packages. But as stated in the title, I'm specifically referring to Kubuntu compiled packages. Installing virtuoso will install the rest (everything else is already installed in the default distro).