random bits in badblocks
The option -t random specifies that "the block should be filled with a
random bit pattern".
Now, just how random is that bit pattern.
Does it choose a random byte and fill the entire hard drive with it?
Does it make up a random disk block and write that to the whole disk?
Or does each block get its own randomly chosen data, presumably generated
by a pseudorandom generator so as to catch bad seeks? In this case, is
the seed always the same, so I could take a disk I wrote on with -t
random and check it next week, the computer being off in between?