How to umount when the device is busy in Linux

    # umount /media/disk/
    umount: /media/disk: device is busy
    umount: /media/disk: device is busy

First thing you’ll do will probably be to close down all your terminals and xterms but here’s a better way. You can use the fuser command to find out which process was keeping the device busy:

    # fuser -m /dev/sdc1
    /dev/sdc1: 538
    # ps auxw|grep 538
    donncha 538 0.4 2.7 219212 56792 ? SLl Feb11 11:25 rhythmbox

Rhythmbox is the culprit! Close that down and umount the drive. Problem solved!