root@Laptop:/home/heinz/Desktop/iPL# mkfs.ext3 /dev/sda3
mke2fs 1.39 (29-May-2006)
Could not stat /dev/sda3 --- No such file or directory

Das Gerät scheint nicht zu existieren, haben Sie es richtig angegeben?
root@Laptop:/home/heinz/Desktop/iPL# sudo fdisk -l

[...]

Disk /dev/sda: 30.0 GB, 30005819392 bytes
255 heads, 63 sectors/track, 911 cylinders
Units = cylinders of 16065 * 2048 = 32901120 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1               1           3       96264    0  Empty
/dev/sda2              21         911    28627830    b  W95 FAT32
/dev/sda3               4          20      546210   83  Linux

Partition table entries are not in disk order
root@Laptop:/home/heinz/Desktop/iPL#