Torsdag 23. april 2009, skrev RalfGesellensetter: > Klaus Knopper replaced KDE by LXDE to reduce startup time (especially > for netbooks), and thus I have been using this new desktop > environment for some weeks, now.
Skolelinux 3.0 is running LDM as a login manager on thin clients with LTSP. This is slower than KDM. You can replace LDM with KDM, and speed things up a little. But you'll miss the secure ssh tunnel which has some security benefits clients connected to a network hub. When running a switch, package sniffing is not as easy. Second issue is not as obvious. It's about memory usage. Replacing the KWin Windows Manager with which is default in KDE with LXDE, may use more memory in the most common usage of the client machines. This article[1] explains how and why: 1. http://ktown.kde.org/~seli/memory/desktop_benchmark.html This memory walk trough is backed up by several municipalities and businesses. They states that they run 50-60 thin clients with KDE on LTSP servers with 4 GB RAM. Some even run 70 clients with such memory configuration. Other Windows Managers only allow 30-40 clients in the most common use cases according to system administrators. How does such numbers scale? When running 1000 thin clients or more at schools with the servers placed centrally at town hall, they can manage this with 16-17 servers running KDM+KWin+KDE. Or they can go for 25 servers with an other Windows Manager. It may not seems a big difference when running one server. But when running 1000 clients or more, a difference between 17 and 25 is 8, which may cost 18.000 Euro for those additional servers. And is this economic climate, such numbers can be decisive. That said. I was in Narvik this weekend. They had added 4 more GB with RAM on their 5 years old servers, now having 8 GB RAM. Then they added more thin clients and low fat clients (diskless) to the servers. They also enforced the network with better switches for handling the network load. > I've always been a big fan of KDE (and contributed within my > possibilities to the KDE project), but I also like the lite and yet > comfortable appearance of LXDE. Especially for less powerfull > hardware, this desktop is a real alternative. The strong point of LXDE is on netbooks with a smaller screen, cause the lxlaunchers tabbed menu[2][3]. Ubuntus netbook remix launcher seems to have taken this a small step further[4]. 2. http://lxde.org/lxlauncher 3. http://lxde.org/lxlauncher_simple_tab_set_according_freedesktoporg_standards 4. http://www.markshuttleworth.com/wp-content/uploads/2008/06/nb-remix- launcher.png > The backdraw must be mentioned: While the desktop comes up very > quickly, many stuff is only loaded just in time (causing pauses > during work); this includes sub-menues of the start menu, and of > course libraries and daemons (qt/DCOP for instance). KDM boots fairly quick on thin client machines run from a central server. Yes, some other Window Managers allow faster startup. But often other things slows things down even more, as work done by Intel shows[5]: 5. http://www.linuxdevices.com/news/NS7654890804.html > Regarding the LTSP usecase, most services have been started right > beforehand, anyway, so popcon should tell us more - > > and of course, your personal comment to this thread Strangely it's LDM which are slower than KDM (the KDE login manager) in Skolelinux. The reason? We had to address some security concerns on networks with hub's. The startup issue is an ongoing story, especially now with netbooks, Mobile Internet Devices and Linux on phones etc. E.g the startup of KDE4 is dramatically reduced cause of a total cleanup of the libraries compared to KDE3. The libraries needed in KDE4 is reduced with approximately 60-70 percent compared with KDE3. Also Qt4 libraries beats the dust out for Qt3 performance wise, where Qt4 is made for phones and embedded devices. Qt3 was not really used on phones. Also, KDE 4.2 is not really ready for huge deployment yet. 4.3 will be the first version for such large installations we see at schools. KDE4.2 has not gotten all the essential KDE3 applications ported to Qt4 and KDE4 yet. Then some KDE3 applications are still running, as you can see with Kubuntu 9.04. This configuration uses more memory. Then you're Linux box is running both a KDE3 and KDE4 library stack. This situations will change soon, since the last applications (as KMix) are now ported. Then sticking to KDE 3.5 in Skolelinux two more years is not a big thing (including a Gnome for those who prefer that). But running the latest and greatest on netbook with additional bling as KDE4 gives, is a really good thing. Giving Windows users a better than Vista experience on a Linux desktop. This may make a difference - shown in this hilarious reportage done by ZDnet in Australia: http://www.zdnet.com.au/insight/software/soa/Is-it-Windows-7-or- KDE-4-/0,139023769,339294810,00.htm Best regards Knut Yrvin -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]
