IMG

• dd vs fallocate vs qemu-img for creating .img file:
  • dd does not leave holes (use bs=4M for faster copying)
  • fallocate is much faster, but leaves holes
• Prefer partx to kpartx; the latter is complicated and depends on device mapper, while the former simply notifies the kernel about partitions

References

• https://askubuntu.com/questions/1017309/fallocate-vs-dd-for-swapfile
• https://git.adelielinux.org/adelie/bootstrap/-/blob/master/bootstrap?ref_type=heads
• https://roscopeco.com/2013/08/12/creating-a-bootable-hard-disk-image-with-grub2/