rainer wrote: > Hi all, > > After updating my FC4 installation to FC5, I noticed that my > external 230GB USB hard disk became very slow. It also became quite > noisy since the disk heads were moving all the time, even if there > were only small amounts of data being written to the disk. It took > me a while to find out what happens: > > The USB drive is mounted automatically in asnyc mode. Looking at > /etc/mtab, I can see the following entries for the 3 partitions on > the disc: > > /dev/sdb1 /media/lin1 ext3 rw,noexec,nosuid,nodev,sync,data=ordered 0 0 > /dev/sdb2 /media/win1 vfat rw,noexec,nosuid,nodev,noatime,uid=500,utf8,shortname=lower 0 0 > /dev/sdb3 /media/lin3 ext3 rw,noexec,nosuid,nodev,sync,data=ordered 0 0 > > I can fix the problem by remounting the partitions manually, e.g. > mount -o remount,async /dev/sdb1 > but it is quite annoying to do this every time I plug in the drive. > > My Questions: > * Is this common behaviour in FC5 or due to some misconfiguration in my system? > * Shouldn't this be treated as a bug? > * What is the best workaround? (I am using KDE, if that matters) > It is becoming common to keep people from loosing data when they unplug a USB drive without unmounting it and waiting for the drive to finish before unplugging the drive. With non-removable drives, the system does write caching, so there may be unwritten data in the buffers. This allows the system to be more efficient when writing to disk. But if you unplug the drive without flushing the cache, you loose data. The sync option turns off the write cache, so data gets written to disk right away. The good part is that the chance of data lose it greatly decreased. The bad part is that performance suffers. You can change the default mount options by changing the HAL rules, or add a rule for that specific drive. But before you do, you have to decide if you want to take the risk of loosing data. Mikkel -- Do not meddle in the affairs of dragons, for thou art crunchy and taste good with Ketchup!
