mmcblk0p2 is actually optfs and you cant unmount it while device is on. MyDocs is mmcblk0p1 and mmcblk0p3 is swap memory
BusyBox v1.10.2 (Debian 3:1.10.2.legal-1osso30+0m5) built-in shell (ash) Enter 'help' for a list of built-in commands. ~ $ root BusyBox v1.10.2 (Debian 3:1.10.2.legal-1osso30+0m5) built-in shell (ash) Enter 'help' for a list of built-in commands. Nokia-N900:~# umount /dev/mmcblk0p2 umount: cannot umount /dev/mmcblk0p2: Invalid argument Nokia-N900:~# fsck.vfat -aw /dev/mmcblk0p2 dosfsck 2.11, 12 Mar 2005, FAT32, LFN Logical sector size is zero. Nokia-N900:~#
Pm sent. Try backupmenu and gparted from GParted-Live-CD or ubuntu- / debian-based Live-CD, please.