On Sun, 2005-05-22 at 15:25 -0600, Michal Jaegermann wrote: > On Sun, May 22, 2005 at 10:08:21PM +0200, Ren�an Paassen wrote: > > Inserted a usb 2.0 disk, and the thing duly shows up on /media/usbdisk > > However, writing was painfully slow, order of 100 kB/s > > That is most likely because hal is mounting removable USB devices > with 'sync' option. Personally I think that this is insane and > will cause numerous complaints and claims that Linux is extremely > slow but this is supposed to be "idiot-proof". > > Mounting sync is really bad for a writing speed, and likely quite > bad for "USB sticks" even if they do "wear levelling" in a > reasonable way, but gives you a fighting chance that you did not > screwed up your data and/or a file system on that device if you > pulled it out without unmounting first. Mind you - only a chance > and very far from guarantees. Of course if you will kill your USB > memory stick in the process this is not much of a gain. > > There is some possibility that you can change that policy on your > machine if you will be able to figure out how - which is hard to > call "documented". > The next build will not use the 'sync' option, mainly because of performance reasons (now that O_SYNC works for vfat). See also https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=157674 > > Tried a second disk, this one would not automount. After manually > > mounting it (/dev/sde1) it ran well, with normal writing speed. > > A default for mount is 'async' so you will see what you see unless > you asked otherwise. > > > Inserted the original disk again, and would not automount. After manual > > mount (/dev/sde this time) it also ran well. This is due to a kernel bug which mixes up the order of hotplug events and does other things that confuse userland in interesting ways. https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=156167 David