tar, cpio, dd

[sonun]

I mostly use tar but I heard some people say that sometime cpio and dd would work where tar would fail. I fail to understand how. Anyone want to educate me??
Also, whats the cpio and dd equivalent of,
tar cvf /dev/st0 /foldername
I tried a few options, but am still unable to get hold of the proper format.
Thanks.

 

[KenCunningham]

Try cpio -ocvB <folder> > <devicename>

tar sometimes complains about the size of a file it's asked to save.

Regards.