So, as I noticed, MacOS X's Disk Utlity doesn't allow to make a copy of the whole disk, only it's partitions (which sucks, as bootloader won't be copied then.). As both my laptop's hard disk and my spare external hard disk are both seagates 320gb (one is 7200rpm, second is 5400rpm), I've decided to make a copy of my disk onto my external, as it's doing nothing at the moment. So, I'm going to use dd command. However, I've had some... bad times with dd, so I'm little paranoiac now.
As now, I'll try to do this -
dd if=/dev/disk0 of=/dev/disk1.
But then, I don't know whether it's correct. I don't know what's the difference between /dev/diskNumber and /dev/rdiskNumber, and google found me nothing. so which one should I use? Also, what should i set as block size? Leave it blank, or set bs=512? Calculate the count value or leave it blank?