└─▪ sudo apt-get clean && sudo apt-get install --reinstall mount Reading package lists... Done Building dependency tree Reading state information... Done Suggested packages: nfs-common The following packages will be upgraded: mount 1 upgraded, 0 newly installed, 0 to remove and 17 not upgraded. Need to get 114 kB of archives. After this operation, 0 B of additional disk space will be used. Get:1 http://ftp.tu-chemnitz.de/pub/linux/ubuntu/ trusty-updates/main mount amd64 2.20.1-5.1ubuntu20.7 [114 kB] Fetched 114 kB in 1s (89,1 kB/s) (Reading database ... 195214 files and directories currently installed.) Preparing to unpack .../mount_2.20.1-5.1ubuntu20.7_amd64.deb ... Unpacking mount (2.20.1-5.1ubuntu20.7) over (2.20.1-5.1ubuntu20.6) ... dpkg: error processing archive /var/cache/apt/archives/mount_2.20.1-5.1ubuntu20.7_amd64.deb (--unpack): unable to install new version of `/bin/umount': Device or resource busy Processing triggers for man-db (2.6.7.1-1ubuntu1) ... Errors were encountered while processing: /var/cache/apt/archives/mount_2.20.1-5.1ubuntu20.7_amd64.deb E: Sub-process /usr/bin/dpkg returned an error code (1)