I am attempting to clone a disk partition to an image file using dd. I want to create the image without zeros to minimize the filesize, and on the other hand I do not want to pipe through gzip. The solution I found consists of writing zeros to a dummy file until the disk is full. The problem I am running into is this is a FAT32 filing system, so I am limited to making these dummy files 4.3GB. Tedious to say the least.
My question: If I have an already zero'd drive with a new partition table and freshly written data to the partition... would I be safe to skip the "filling the free space" step and just go right to running dd using conv=sparse? The entire drive had been zero'd out prior to partition creation, so I am confident that the free space should already be zeros.