[viddi]

Two years ago, I had to clone a disk image from one UEFI notebook over to another identical one. Using gzip with output redirection to the device file (might also have been zcat or cat with gzip) did just not work. After days of unsuccessful attempts, I resorted back to dd with gzip. And believe it or not: Only with dd the disk clone was successful.

I came as far as comparing the image files, which were identical, but I did not have the time to compare the disks. So, this still is a mystery for me.

On a side note: If you ever need to do a full disk clone nowadays, I can only recommend clonezilla. Using FAI (Fully Automatic Installation) would be even better instead of doing image clones, but sometimes, that's not an option.