Heavy duty harddisk check. A file in the filesystem, a partition on a disk or even a hole disk (in fact any file) will be written with crc-checked random-filled buffers. in the second stage those blocks will be randomly read from the file an the crc-sum checked. also several times new blocks are written. errors are logged. this programm simulates a usal harddiskacess under a heavyly loaded system and brings up bugs in the os, the hardware or even the firmware of the harddisk.