Category Archives: Linux

Is the KDE 5 desktop stable enough for normal users?

This not a rant! I just want to share some concerns about the quality of the current KDE desktop and its deployment to normal users.

I upraded to KDE 5 by upgrading from Fedora 21 to Fedora 22. I did this rapidly on four laptops because I liked the new fresh look. Two of them I use heavily for personal work. The plasma version in use was 5.3. But after some weeks of work I collected a long list of heavy issues with that desktop. They all showed up doing very general things. Especially problematic are multi screen configurations. Things you usually do when you plug in and plug off your laptop from the display at your working place.

Here is a (incomplete) list of issues I currently face with the plasma desktop 5.4

  • Attaching and removing screens from the laptop does not change the screen configuration. That means attached screens get not actived and removed screens not deactivated. Usually I have to reconfigure the screens manually in systemsettings. Afterwards killing and restarting plasmashell is required, exspecially to get rid of disconnected screens. If that does not help I usually try restarting kwin too, although I’m not sure that helps. Multi-screen switching somewhat worked with plasma-5.4 but broke again with a kdeframework upgrade. If you have configure multiple panels in a multi monitor setting you can find them jump around (even stacking) if you change anything in the screen positioning. If you attach a new screen and activate it, sometimes plasma moves on to the new screen (good!) but the old screen gets black. I can move windows onto it but there is no plasma running in its background (bad). But that is relatively small bug.
  • As not all applications have been moved to KDE 5 yet, some of them use kdewallet4 and some use kdewallet5. This means that you are asked for a password to open the wallet twice in the same session – and those passwords can be different! Even if you know that you often have to try one password and after that the other one. Since the last updates the kdewallet5 password window can be visually distinguished from the kdewallet4 one what helps me with that. This is not a real bug but very very uncomfortable for users.
  • The digital clock applet just stops and shows an old time.
  • The digital clock applet will never show another timezone than UTC if UTC is your system timezone, no matter what timezone you configure in its settings. Really I never had so much problems getting the correct time displayed on my desktop – because I had not find out that the system time ist the problem.
  • The window taskbar gets out of sync with the application windows. That means you can click on firefox in the taskbar and what open up is a dolphin window (or no window at all).You see taskbar entries for applications you have closed and you miss them for ones you have opened.
    When you have two screens with two taskbars each of them configured to show only the windows of the current screen -> windows get mixed up and are shown in the wrong taskbar. Worst: Sometimes the taskbar(s) do not work at all. Praise the “Show windows” desktop effect, it saves your day.
  • krunner will sometimes not execute commands. In that case I have to restart plasmashell via terminal.Very annoying because I have to do that often.
  • krunner sometimes does not appear at all (maybe fixed in 5.4)
  • If you have two screens with two identical panels, sometimes applets in one of the panels will not be able to show a plasma popup on one of them. That means if you have a application starters on your right and left screen, the application starter just works on the left one. (maybe fixed in 5.4)
  • After having changed the screen positioning the plasma applets do not recognize that and do open somewhere on the screen and not beside the panel (maybe fixed in 5.4)
  • Moving plasma pannels between screens works only with patience and it is really messy. This becomes a problem in conjunction with the issues making panels jumping around on screens in dynamic multi-screen configurations.
  • On three systems with intel based graphics of different generations I did not find one with a opengl version and interface combination which did not sometime create a garbled screen. I know that the linux graphic stack is a nightmare and the fault is likely in there exspecially as Fedora is on its bleedings edge side. But this was better in plasma 4.
  • UPDATED: File search in dolphin does not work at all. It never finds anything.

This is the situation now – and it is much better than it was when Fedora 22 came out with Plasma 5.3.

I found the following additional heavy problems in the plasma 5.3 desktop (which has been shipped out to end users by various distributions):

  • Migration from kdewallet4 to kdewallet5 lets you enter a password for the new wallet. Unfortunatly the password you enter did not work to open the new wallet afterwards. I had this on three systems and I’m sure I did not make a typo three times. The problem got fixed afterwards but the systems upgraded with that bug are somewhat of broken. There is no obvious way to get a new working system wallet.
  • Plasma animations running long start to eat up one CPU core completly. This means if the network applet tries to connect too long or telepathy tries to connect to IM accounts with broken down servers (making the panel icon spin all the time) you burn your laptop battery. Oh – and do not do long file transfers with dolphin because the progress spinner in the panel will fight with the copy process for cpu cycles. This bug has been fixed in 5.4 but people report to still see it occasionally.
  • Too many windows caused plasma to eat one CPU core too. I often work with several firefox windows. The second one usually made the whole desktop slow and made plasmashell burn half the cpu power. The problem went away when the window was minimized. So you were not supposed to have more than a few windows open in plasma 5.3. I think system memory is something that can limit the amount of open windows – your desktop should not.

That bugs made me step away from KDE until plasma 5.4 was pushed out in Fedora. The last time I did that was during the KDE 4.0, 4.1 time frame.

These are just the bugs I was able to clearly identify and reproduce. I had many more problems. SDDM was some kind of a nightmare when it became the default for KDE. I had heavy problems with it in a multi screen setup and I could not login into a second session. I had to fall back to kdm several times. Luckily the heavy problems have been mostly sorted out in recent updates. Ktelepathy is another area where I had my problems. I migrated to it from pidgin mostly because plasma 5 did not support the old sysicons anymore. Ktp has its issues exspecially when using the OTR plugin and having contacts that are logged on several computers (sending and receiving messages does not always work). I hope to get into good working order by not using OTR anymore and with the latest updates. It still has a preference for crashing plasma when using the contact list applet. Since three weeks its systemsettings module crashed when I tried to modify a specific IM account of mine. Well, I had to delete and recreate it.

I did not search for all of the listed bugs in bugzilla. The ones I search for I found there reported. The bugs are so obvious that I’m sure they are all reported. I’m not sure which bugs are caused by the distribution (Fedora). Maybe a few that I did not look for. I mostly can rule out that they are caused by old config files because I tried to fix them by deleting the old ones several times. The bugs show up even using fresh user accounts.

I find it very hard to work with the KDE desktop in its current state. Again, this is not a rant. I do not complain. I have no time to help development, I live with what I get. I’m sure developers to their best to enhance the situation. I can just say: This is the first time that I’m really not interested in updates because of new features or performance enhancements. I just wish myself bugfixes.

What puzzles me is that plasma desktop is widely reported to be a stable desktop

I have not seen a review of KDE (or a distribution using it) mentioning any of the problems I am seeing daily. This is somewhat of explainable: You will not find the bugs without really working with the desktop. You have to use it some days, do your work on it and plug your device on to different monitor. Unfortunatly I think most press reviewers do not do that. You can cope with the current KDE if you have just one screen, always a stable network connection and restart daily. You normaly do not work under such conditions, do you?

Would I’ve known that KDE 5 has so much rough edges – I just would not have installed it on my production systems. Fair enough. Oh – and I would not have upgraded my wifes computer who thanked me with “No more updates ever! This does not work at all!” And she was even right.

The reality is that I do not see how one could cope with current plasma desktop without good knowledge of the system and the ability to restart kwin, plasma or the whole session from the command line. In the same time I see this desktop being pushed out by many distributions to normal end-users. I personally often try to migrate normal people from Windows to a Linux Distribution. This often works quite well. But would I try to give one of them the current KDE desktop, I’m sure I would not succeed in freeing the person. My problem is: That’s what distriubtions currently do and I do not see one word of warning.

Either the problems I list are just happening to me – or users should be warned that they should currently stick with KDE 4.12 if they are neither experts nor brave. I consider plasma 5.4 somewhat useable for me, but in my opinion plasma 5.3 was too heavily broken. Nonetheless it was shipped by Kubuntu and Fedora. Fedora is a bleeding edge distribution (meaning that is okay), but Kubuntu is directed at less experienced users.

Nevertheless, especially because I had to switch desktops in the last months to get work done, I can only say that I still find KDE the desktop I like most. I just hope that it lets me use it more easily.

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Start a service after openvpn connection has been established using systemd

I like to provide services only via VPN for security reasons. That means a server only accepts connections to a service (e.g. imap, jabber) only from a vpn network and not coming from a really network device. Usually it this is easy to do by configuring a service to just listen on the vpn interface.

Unfortunately this creates a problem when starting up a machine. The vpn connection is usually established some time after the networking is established. The services that should listen on the vpn interface are usually started before the vpn service has setup the vpn connection. Most services fail to startup in that case because the interface they should bind to is not there (yet).

Systemd can be configured to start the services in the right order but I found it hard to find working advice for doing that. So this is the way.

  1. Create a copy of the .service-file responsible for the service you want to start after openvpn in /etc/systemd/system. This is required as you are not supposed to ever modify .service files in /usr/lib/systemd directly.

    cp /usr/lib/systemd/system/[yourService].service /etc/systemd/system

    Units found in /etc/systemd/system will overrule the units from /usr/lib/systemd/system
  2. You need to modify the copied service file in /etc/systemd/system. Place this lines in its [Unit] section:

    [Unit]
    Wants=sys-devices-virtual-net-tun0.device
    After=sys-devices-virtual-net-tun0.device

    Note: If there are already Wants or After directives in the file, place the sys-devices-virtual-net-tun0.device behind the existing directive seperated with a space. Wants and After accept multiple units but they must be space seperated.
    Note: This assumes that the vpn you want the service to wait creates the tun0 device. Systemd creates units files for network interfaces that show up. The lines above make systemd wait for tun0 to show up before it starts the modified service.

When you have enabled your service with “systemctl enable” it should now startup after the vpn connection has been established.

This should work with any vpn technology as long as you make sure to use the right device file. If your vpn is behind interface tun1 you should use sys-devices-virtual-net-tun1.device instead of sys-devices-virtual-net-tun0.device.

Fedora 20 on the Omnibook 4150B

I successfully upgraded this pre 2000 laptop to Fedora 20. Everything went smooth. You can hardly see a difference.

Still, the laptop is missing a usage because of its slowness. Even watching videos became hardly possible after some acceleration drivers for the old mach64 chipset had been removed from Xorg.

The situation will become worse when the drivers for old graphic chips will be purged completely in Fedora 21. From then on only VESA drivers will be available for showing a desktop.

If someone still wants to run a desktop on such an old machine, the current debian stable release is probably a much better choice.

Fedora 20 with Gnome 3.10 works again on the wetab

After having input problems in Fedora 19 (previous post) which made the Gnome desktop unuseable – I can now happily confirm that the problem is solved in Fedora 20. I can work with Gnome 3.10 as you expect it on the touchscreen.

The system is running quite slow nonetheless. This may be caused partially with the SSD slowing down during write access – but what can you do about that with an SSD without TRIM support?

Fedora 19 on hardware of the last century

Another six month have passed, so my good old laptop from pre-20IMG_220900 got another update.  I updated the already running fedora 18 to fedora 19 by using the fedUp tool.

The update took longer than on more recent systems (of course) but it worked flawlessly.

After that I booted into the LXDE desktop of Fedora 19. Everything worked as before. The machine is still too slow for most uages, even webbrowsing is painful. Work with libreOffice is probably doable.

Still, one big downside of modern linux distributions is that there is no video acceleration for this old graphic chipset anymore. So most videos can not be played. On the positive side, I was surprised to find that suspend to ram and suspend to disk both worked flawlessly on Fedora 19. Good work to remain compatible with APM (pre-ACPI)!

Ubuntu 13.04 and Fedora 18 on the Wetab

You might remember this tablet that came out from Germany in parallel with the iPad. It’s more or less a netbook with a touchscreen but without a keyboard. It hat some drawbacks, the worst in my opinion is the bad screen. You can switch the small SSD in it, but you cannot replace the screen. Bad. The device ended not being used anymore shortly after I bought a used one.

Anyway, I wanted to use the wetab as a (network) tv display wall-mounted in the kitchen. That’s why I started to throw a modern linux distribution on it. I always used the 64-bit images because they are known to run faster on the CPU (at the cost of slightly increased memory usage).

Ubuntu 13.04

In short: Ubuntu was not running on the wetab for me.

Long version: The install image is loading correctly from a usb stick. Everything looks good – unity is not a bad touch experience. The downside comes after you have installed Ubuntu on the wetab. The system does not get to a usable system. The desktop is visible (in a wrong resolution) but there is no reaction to input. Even if you connect a keyboard to the tablet, you cannot do anything. The keyboard is not initialized correctly.

I was not able to find out the source of the problem. Examining log files made clear that the Vesa graphics driver is loaded instead of the intel one. That’s wrong and explains the wrong resolution with which the desktop is started. However it does not explain why the tablet does not react to any input. Why Ubuntu works from usb but not when being installed remains a mystery.

I tested Ubuntu 12.04 too and it had exactly the same problem. So I don’t expect a fix for this any time soon.

Fedora 18

IMG_0441

I gave Fedora 18 a try afterwards. To my surprise it was fully functional out of the box. After installing it boots into a Gnome 3 desktop. I found Gnome 3 less attractive than unity in this touch usecase, but as far as I know Gnome 3 is the only touch friendly desktop in Fedora. I can live with it.

Fedora 18 and Gnome need some more finishing touches than Ubuntu. The default installation is not really lightweight. But you can turn of some programs and services after installation. If you do that, you can bring memory usage in the area around 300 MiB. The remaining RAM should be enough for watching video streams and some surfing.

My browser choice fell on Chrome. While the low memory available on the wetab (1 GiB) suggests using Firefox with its lower memory footprint, Chrome is able to use some acceleration for displaying webpages. As the wetab is not planned to do many things at the same time but is supposed to do one task as fast as possible, the choice was clear for me here. Chrome has a nice touch extension which really makes it fun to use.

The performance of gnome 3 on Fedora 18 on the wetab is acceptable. What impressed me most is that the screen is rotated automatically when you turn the tablet. This works out of the box.

All in all I find the wetab to be really good supported by Fedora 18, what is surprising after the big problems that showed up with Ubuntu.

Build your own 6 watts home server using an raspberry pi

IMG_1513 In the picture besides you see my new home server built around a raspberry pi. The parts in detail:

  • raspberry pi model b Rev.2 inside a transparent casing
  • D-Link DUB-H7 7-Port USB 2.0 Hub (confirmed working with the raspberry pi)
  • 2.5 inch 500 GB usb harddisk from toshiba (an older one I had)
  • Hauppauge Nova-T Stick for DVB-T (confirmed working with the raspberry pi IF you have a powered usb hub!)

The pi is connected to a fritzbox 7270 via ethernet and is running raspian (Debian Wheezy). The CPU is overclocked a little at 800 MHz.

Currently this small computer is running the following services for me:

  • full webserver consisting of nginx, php and mysql (follow standard tutorials for debian)
  • web rss reader using tiny rss 1.7.4
  • streaming tv from the tv stick to all computers in the network using vdr and streamdev-plugin
  • streaming requested music via the upnp protocol having installed minidlna as described here
  • common file storage via ssh/sftp
  • backup space via rsync

Memory usage is around 100 MiB all the time (no graphical is running). TinyRSS could be running a little snappier – I intend to help optimizing it a little. Streaming tv is putting 15% cpu usage on the pi.

The best about it is the low power usage. I measured it and even together with the power supply it never reached 8 watts. I see around 5 watts at idle. It may peak a little higher when there is full cpu and disk load – but that’s rare. So you can think of having it running all day without some bad.

I intend to add another usb disk acting as a backup by mirroring the data on the other disk.

Things to know about power usage

Power supply was the only big question I had when putting together the parts I needed. I wanted to keep costs and power losses low by running not adding more power supplys than absolutely needed.

The raspberry pi can be powered via an usb port. But it needs at least 700 mA what not every port provide. The usb port of the Fritzbox was no option because of that. If you want to connect more power hungry devices (like harddisks or tv sticks) via usb to the raspberry, you really need a powered usb hub because no usb port can power the pi AND that devices together. I wanted to run the pi, two harddisks and a tv stick altogether, so some power was needed.

Instead of buying a power supply for the pi and a powered usb hub (which would make two), I only bought the usb hub. The D-Link hub is specified to deliver 3.5 A, what should be enough. So I simply pluged the pi into the hub and connected the hub with the pi via one of its two usb ports again. This connection circle is working well and every device I plug in the hub can be used by the pi. This trick saved me one power supply and some power being burned.

A hint if you intend to run usb disks with that hub: Have Y-cables available (with two usb plugs). One port of the hub may not be enough to power the disk, but using two of them will suffice.

Update 30.5.2013

In the meantime I added a second USB harddrive to the setup which serves as a backup. Via cronjob the content of the first harddisk is transfered to the backup disk every night by rsync. That works perfectly.

Moreover I have a cronjob making a low level copy of the sd card containing the system image to the hard disk weekly. So I have a full backup of the system in case the sd card is failing.

Two problems I encountered. Mirroring my desktops home directory to the usb drives of the pi via rsync often crashes long before having finished. I do not know the reason but found rsync to be no backup solution for me. Maybe unison will work here.

Apart from that I sometimes find that my tv stream from the pi suddenly aborts and cannot be restored. It took me a while to find out that the problem is actually the fritzbox 7270 running FritzOS 5.50. After restarting it, everything works again. Must be a strange  bug in the fritzbox with data intensive socket connections. So if you are watching tv via your pi and the stream aborts, the problem might actually be your router.