Clone OS image

Read disk and save .img.xz

$ sudo fdisk -l

...

Disk /dev/sdb: 14.86 GiB, 15931539456 bytes, 31116288 sectors
Disk model: STORAGE DEVICE
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: dos
Disk identifier: 0xf7bdbfa9

Device     Boot  Start      End  Sectors  Size Id Type
/dev/sdb1         8192   532479   524288  256M  c W95 FAT32 (LBA)
/dev/sdb2       532480 31115263 30582784 14.6G 83 Linux

sudo umount /dev/sdb1 /dev/sdb2

sudo dd if=/dev/sdb of=clone.img bs=4M count=$((31115263 + 1)) status=progress

$ sudo parted -ms clone.img unit B print
BYT;
/home/hhk7734/clone.img:15931539456B:file:512:512:msdos::;
1:4194304B:272629759B:268435456B:fat32::lba;
2:272629760B:15931015167B:15658385408B:ext4::;

$ sudo losetup -f --show -o 272629760 clone.img
/dev/loop20

sudo e2fsck -pf /dev/loop20

$ sudo tune2fs -l /dev/loop20 | grep -e '^Block size:' -e '^Block count:'
Block count:              3822848
Block size:               4096

$ sudo resize2fs -P /dev/loop20
resize2fs 1.45.5 (07-Jan-2020)
Estimated minimum size of the filesystem: 851980

sudo resize2fs -p /dev/loop20 $((851980 + 5000))

sudo losetup -d /dev/loop20

sudo parted -s -a minimal clone.img rm 2

sudo parted -s clone.img unit B mkpart "primary" "272629760" \
    "$((272629760 + ((851980 + 5000) * 4096)))"

$ sudo parted -ms clone.img unit B print free | tail -1 \
    | cut -d ':' -f 2 | tr -d 'B'
3782820352

sudo truncate -s 3782820352 clone.img

sudo xz -vk -T$(($(nproc) - 2)) clone.img

Flash .img.xz to disk

xzcat -dvk -T$(($(nproc) - 2)) clone.img.xz \
| sudo dd of=/dev/sdb bs=4M status=progress conv=fsync

or Use Etcher.