Am Di., 22. Apr. 2025 um 19:17 Uhr schrieb Sean Snell <ssn...@lakecs.net>:
> *> which I encountered during copying this ISO image over.* > > If you were trying to write the ISO as-is for bootable reuse wouldn't you > use DD to write the image as it stands? Otherwise if keeping the ISO as an > ISO was your goal wouldn't you need to create a basic partition table, > mount the partition (ie /dev/sda1 to /mnt) then *cp archlinux.iso /mnt* ? > I was providing an USB pen drive with the current version of the Arch Linux bootable ISO image. cp archlinux.iso /mnt/ would be pretty useless, as it would just copy the ISO file into the directory /mnt. Instead, I copied over the ISO "in raw" directly to the special device file /dev/sda, s.t. it becomes the content of the corresponding device (the pen drive here) directly, so it can be booted later on. In fact, it doesn't matter which program opens that device file /dev/sda. All the translation to the raw memory of the device is done by the kernel. So it doesn't matter if dd or cp is used. In this respect, the *work is not done by* dd. It is not even much faster. For both programs, /dev/sda is used as a file lying around in /dev/, which is opened in writing mode, and whose content is overwritten. > Apologies if I've misread, you've sparked my genuine curiosity with the > path you've chosen. > At this point, the ingenuity of "device files" becomes apparent. I always find it a pretty genious way of exposing devices in a filesystem tree. Best, Friedrich
