linuxgeek: [LINUX_Newbies] Is the stick mounted after all or not? Linux isn't sure, it seems

Hey all,

could someone point out the logic of the following output when first I wanted to look up which drives were mounted and then umount a BTRFS-formatted USB pen drive? The relevant line are preceded and followed by a line of asteriks, hope that makes it easier to grasp what I'm at.

root@Bodhi-Mobile:~# mount | column -t
/dev/sda5 on / type ext4 (rw,errors=remount-ro)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
/dev/sda1 on /boot type ext3 (rw)
/dev/sda7 on /home type ext4 (rw)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
gvfs-fuse-daemon on /home/pascal/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=pascal)
*************************************************************************************************************
/dev/sdb1 on /media/Backup-BTRFS type btrfs (rw,nosuid,nodev,uhelper=udisks)
*************************************************************************************************************
/dev/sdc1 on /media/XFS-Stick type xfs (rw,nosuid,nodev,uhelper=udisks)
/dev/sdd1 on /media/Sync-Stick type ext4 (rw,nosuid,nodev,uhelper=udisks)

*************************************************************************************************************
root@Bodhi-Mobile:~# umount /media/Backup-BTRFS
umount: /media/Backup-BTRFS: not mounted
*************************************************************************************************************

Then again, I checked:

root@Bodhi-Mobile:~# mount | column -t
/dev/sda5 on / type ext4 (rw,errors=remount-ro)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
/dev/sda1 on /boot type ext3 (rw)
/dev/sda7 on /home type ext4 (rw)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
gvfs-fuse-daemon on /home/pascal/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=pascal)
*************************************************************************************************************
/dev/sdb1 on /media/Backup-BTRFS type btrfs (rw,nosuid,nodev,uhelper=udisks)
*************************************************************************************************************
/dev/sdc1 on /media/XFS-Stick type xfs (rw,nosuid,nodev,uhelper=udisks)
/dev/sdd1 on /media/Sync-Stick type ext4 (rw,nosuid,nodev,uhelper=udisks)

The stick in question wasn't even plugged in at that moment. This happens regularly with this stick, probably due to the BTRFS-filesystem my Bodhi-Linux somehow is overstretched to handle correctly. In this instance the stick was registered as mounted even after a reboot (and removal of the stick from the USB slot).

Linux seems to be getting better every day!!!