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Recently I noticed the problem, that I could write only with speeds of about 500kByte/s onto USB flash drives. 20MBytes/s should be normally possible.
My observeations so far:
The error message came from my file manager nemo
, and it could be removed by disabling the automount feature of nemo
, since usbmount
keeps track of this task.
nemo -> menu -> edit -> preferences -> behavior -> media handling -> uncheck "Automatically mount removable media when inserted and on startup"
My system mounts a plugged in USB drive automatically on /media/usb0
, or with the suffix 1,2,3. These directories exist on my system permanently. When I plug the drive in the first time after boot, it will be mounted to usb0, after remounting it 3 times, it will be mounted in usb3. On the next replug, it will be mounted e.g. on /media/karl/E2A3-F90D
. All the /media/usb*
dirs cannot be deleted:
sudo rm -R /media/usb0 rm: cannot remove 'usb0': Device or resource busy
usbmount
is a scripted installed on my system and it seems to be run by the udev
-rule in /lib/udev/rules.d/90-usbmount.rules
. It's config is in /etc/usbmount/usbmount.conf
:
# Configuration file for the usbmount package, which mounts removable # storage devices when they are plugged in and unmounts them when they # are removed. # Change to zero to disable usbmount ENABLED=1 # Mountpoints: These directories are eligible as mointpoints for # removable storage devices. A newly plugged in device is mounted on # the first directory in this list that exists and on which nothing is # mounted yet. MOUNTPOINTS="/media/usb0 /media/usb1 /media/usb2 /media/usb3 /media/usb4 /media/usb5 /media/usb6 /media/usb7" # Filesystem types: removable storage devices are only mounted if they # contain a filesystem type which is in this list. FILESYSTEMS="vfat ext2 ext3 ext4 hfsplus ntfs exfat" ############################################################################# # WARNING! # # # # The "sync" option may not be a good choice to use with flash drives, as # # it forces a greater amount of writing operating on the drive. This makes # # the writing speed considerably lower and also leads to a faster wear out # # of the disk. # # # # If you omit it, don't forget to use the command "sync" to synchronize the # # data on your disk before removing the drive or you may experience data # # loss. # # # # It is highly recommended that you use the pumount command (as a regular # # user) before unplugging the device. It makes calling the "sync" command # # and mounting with the sync option unnecessary---this is similar to other # # operating system's "safely disconnect the device" option. # ############################################################################# # Mount options: Options passed to the mount command with the -o flag. # See the warning above regarding removing "sync" from the options. MOUNTOPTIONS="sync,noexec,nodev,noatime,nodiratime,uid=1000,gid=1000" # Filesystem type specific mount options: This variable contains a space # separated list of strings, each which the form "-fstype=TYPE,OPTIONS". # # If a filesystem with a type listed here is mounted, the corresponding # options are appended to those specificed in the MOUNTOPTIONS variable. # # For example, "-fstype=vfat,gid=floppy,dmask=0007,fmask=0117" would add # the options "gid=floppy,dmask=0007,fmask=0117" when a vfat filesystem # is mounted. FS_MOUNTOPTIONS="" # If set to "yes", more information will be logged via the syslog # facility. VERBOSE=no
Calling mount
on a terminal shows these last lines:
/dev/sdc on /media/usb0 type vfat (rw,nodev,noexec,noatime,nodiratime,sync,uid=1000,gid=1000,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro) /dev/sdd on /media/usb1 type vfat (rw,nodev,noexec,noatime,nodiratime,sync,uid=1000,gid=1000,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro) /dev/sde on /media/usb2 type vfat (rw,nodev,noexec,noatime,nodiratime,sync,uid=1000,gid=1000,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro) /dev/sdf on /media/usb3 type vfat (rw,nodev,noexec,noatime,nodiratime,sync,uid=1000,gid=1000,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro) /dev/sdh on /media/karl/E2A3-F90D type vfat (rw,nosuid,nodev,relatime,uid=1000,gid=1000,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,showexec,utf8,flush,errors=remount-ro,uhelper=udisks2)
The mount options are quite different.
The option nosuid
is missing for usb0…usb3, which prevents the normal user to unmount it.
Normally it shows a reasonable writing speed. But recently this changed to very high speeds, and then hanging at 98 or 100%.
Calling sync
in the terminal synchronizes all block devices (as far as I understand). Calling it with time sync
reports the time sync
needed to finish it's job.
Flash drives should not be mounted with the mount-option sync
, since this could cause such issues.