Miscellany

$# df -h:

Filesystem            Size  Used Avail Use% Mounted on
/dev/hda1              36G   12G   23G  35% /
tmpfs                 252M     0  252M   0% /dev/shm
/dev/hdb1              74G   33M   70G   1% /mnt/backup


#Is this a plausible command to wipe the entire disk?
$# mkfs -t ext3 /dev/hdb1

Will this copy hda1 to hdb1, using ONLY 12gigs? (Total usage of hda1), essentially mirroring one disk to the next?
$# dd if=/dev/hda1 of=/dev/hdb1 conv=noerror,sync