If I used dd, I would probably compress the file as it is read. But obviously watching that dd does not complain when writing it's data would be a good thing. Surely any proper disk cloning tool would do the same. And perhaps provide a checksum of the data do potentioal later corruption can be detected.

In the example of kiwi, it computes a checksum of the image it will write to an OEM disk, and after it later writes that image to a new OEM disk, it will check that the written disk image has the same checksum. I would expect that any decent backup/restore program must do the same.

On Fri, Oct 20, 2023 at 10:52 PM bent fender <ksusup@trixtar.org> wrote:

Fri, 20 Oct 2023 20:45:07 +0000 (UTC)
Robert Webb via openSUSE Users <users@lists.opensuse.org> :

> On Fri, 20 Oct 2023 12:51:42 +0200, "jdd@dodin.org" <jdd@dodin.org> wrote:
> > Le 20/10/2023 à 10:57, Carlos E. R. a écrit :
> >
> >> If the destination is the same disk size, dd is straight forward, just
> >> copy all. It will not change uuids, that's for some later postprocess.
> >>
> > be warned that similar disks may not have exact same number of
> > sectors/size (specially hdd versus ssd), if the target is even a little
> > smaller than the source, the result may be bad (or not, the worst is not
> > always mandatory :-)
>
> That's why you should always leave a little empty space after the last
> partition on the disk.
> --
> Robert Webb

I never clone entire disks but IF I did I would want the same make and
model and size. As for partitions I make them all exactly the same
size so I can clone any one of them to any other on all disks. The
data partitions , those I back up with rsync.

Disk /dev/sda: 931.51 GiB, 1000204886016 bytes, 1953525168 sectors
Disk model: Samsung SSD 860
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 2CB71AC7-D2DB-4B81-A559-02802643D197

Device Start End Sectors Size Type
/dev/sda1 2048 209717247 209715200 100G Linux filesystem
/dev/sda2 209717248 419432447 209715200 100G Linux filesystem
/dev/sda3 419432448 629147647 209715200 100G Linux filesystem
/dev/sda4 629147648 838862847 209715200 100G Linux filesystem
/dev/sda5 838862848 1048578047 209715200 100G Linux filesystem
/dev/sda6 1048578048 1258293247 209715200 100G Linux filesystem
/dev/sda7 1258293248 1468008447 209715200 100G Linux filesystem
/dev/sda8 1468008448 1677723647 209715200 100G Linux filesystem
/dev/sda9 1677723648 1887438847 209715200 100G Linux filesystem
/dev/sda10 1887438848 1889535999 2097152 1G BIOS boot
/dev/sda11 1889536000 1897924607 8388608 4G Linux swap
/dev/sda12 1897924608 1906313215 8388608 4G Linux swap
/dev/sda13 1906313216 1914701823 8388608 4G Linux swap
/dev/sda14 1914701824 1923090431 8388608 4G Linux swap
/dev/sda15 1923090432 1931479039 8388608 4G Linux swap
/dev/sda16 1931479040 1939867647 8388608 4G Linux swap
/dev/sda17 1939867648 1948256255 8388608 4G Linux swap