If you want to backup a disk or just copy disk to new source dd is the command to do this.
PV(Pipe View) is a good tool to show progress of transfer, but to use PV we might need a size so the % is correct.
To find size to a cd/dvd-rom
Replace X with actual disk number/letter:
OSX:
diskutil info /dev/diskX
There will be a block with “Disk Size:” get the size in Bytes, should be inside ()
*nix:
fdisk -l /dev/sdX
There is a block with “Disk /dev/sdX” get the disksize in bytes
Now lets duplicate
now we have the source bytes size that we can now use with pv to get a complete percent.
Replace X with source diskX og sdX, change SIZE to bytes you just found, and Y to the destination disk
dd if=/dev/X | pv -s SIZE | dd of=/dev/Y