** Description changed: Binary package hint: linux-image I had many performance problems using a usb pendrive: writing large files cause a system slowdown sometimes unacceptable. I performed several tests and in the end the culprit was found to be the CFQ scheduler which is used by default since 2.6.18... CFQ may be good on large system (but I'm not sure), but on a desktop - with one (or two) cpu and only one disk it is unacceptable. + with one (or two) cpu and only one disk and some very slow (but usefull) + devices it is unacceptable. If you are unsure try something like "dd if=/dev/zero of=/dev/sdx" where /dev/sdx is a 4gb pendrive, then try opening a web page... panic! No, not "kernel panic" but "user panic" is guaranteed! Any user that will try ubuntu and need to use a pendrive will think that it work like a floppy disk on win95... For a long time I believed it was a driver problem, but now I'm sure it depends on the scheduler, in fact, I resolved it just adding "elevator=noop". If you care the desktop experience, please, consider the possibility of moving to elevator=noop, at least for the "desktop" version if not for the "server"... I'm having this problem with any ubuntu version with kernel >= 2.6.18 and actually I'm on jaunty with karmic's 2.6.30... A nice lecture: http://www.redhat.com/magazine/008jun05/features/schedulers/
** Description changed: Binary package hint: linux-image I had many performance problems using a usb pendrive: - writing large files cause a system slowdown sometimes unacceptable. + writing large files cause a system slowdown (starvation, may be) + sometimes unacceptable. I performed several tests and in the end the culprit was found to be the CFQ scheduler which is used by default since 2.6.18... CFQ may be good on large system (but I'm not sure), but on a desktop with one (or two) cpu and only one disk and some very slow (but usefull) devices it is unacceptable. If you are unsure try something like "dd if=/dev/zero of=/dev/sdx" where /dev/sdx is a 4gb pendrive, then try opening a web page... panic! No, not "kernel panic" but "user panic" is guaranteed! Any user that will try ubuntu and need to use a pendrive will think that it work like a floppy disk on win95... For a long time I believed it was a driver problem, but now I'm sure it depends on the scheduler, in fact, I resolved it just adding "elevator=noop". If you care the desktop experience, please, consider the possibility of moving to elevator=noop, at least for the "desktop" version if not for the "server"... I'm having this problem with any ubuntu version with kernel >= 2.6.18 and actually I'm on jaunty with karmic's 2.6.30... A nice lecture: http://www.redhat.com/magazine/008jun05/features/schedulers/ -- elevator=cfq (default) cause starvation https://bugs.launchpad.net/bugs/381300 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
