How to copy a Linux installation

Using dd to make a 1:1 copy

Case 1: The Linux installation is on a seperate Harddisk

dd if=/dev/hd[a,b,c,..] of=/dev/hd[a,b,c,..] bs=2M

Part of Sourcedrive  : if=/dev/hd[a,b,c,..] the Letter "a" for the first Harddrive, b for the second, ....

Part of Destinationdrive  : of=/dev/hd[a,b,c,..] the Letter "a" for the first Harddrive, b for the second, ....

Case 2: The Linux installation is on a Partition

(e.g. hda1 is the Partition with the Linux installation and hdb1 is the Destinationdrive)

dd if=/dev/hda1 of=/dev/hdb1 bs=2M