Hi, > does someone know, why when writing an ISO-file with the tool "dd" to an > USB- stick, this stick can not be mounted writable?
This depends much on what the ISO offers as partition tables. $ /sbin/fdisk -l debian-13.5.0-amd64-netinst.iso Disk debian-13.5.0-amd64-netinst.iso: 755 MiB, 791674880 bytes, 1546240 sectors ... Disklabel type: dos ... Device Boot Start End Sectors Size Id Type debian-13.5.0-amd64-netinst.iso1 * 0 1546239 1546240 755M 0 Empty debian-13.5.0-amd64-netinst.iso2 4112 11311 7200 3.5M ef EFI (FAT-12 $ The partition 2 would be mountable rw but with 10 KiB left of 3.5 MB it does not offer much room: $ sudo mount debian-13.5.0-amd64-netinst.iso /mnt/iso $ sudo mount /mnt/iso/boot/grub/efi.img /mnt/fat $ df /mnt/fat Filesystem 1K-blocks Used Available Use% Mounted on /dev/loop1 3576 3566 10 100% /mnt/fat $ It should be possible to find a partition editor which ignores the nested partition situation enough to add another partition to the USB stick. Then you could create an ext4 filesystem on that new partition. > On the other hand, when I am writing the same ISO-image to the stick by > using Unetbootin, the files on the stick are writable. Possibly the same as with Rufus which prefers to unpack the files out of the ISO and to put them into a FAT filesystem on the USB stick. Then it would install a new bootloader or add suitable entries to the configuration of a pre-existing boot loader on the stick. dd'ing an ISO to the base device of the stick (e.g. /dev/sdc) overwrites the pre-existing partition table of the stick. This is necessary for booting directly via the boot loaders inside the ISO. > Is there an option, using dd and let the stick writable iIn case, I want to > edit some files, like syslinux.cfg, grub.cfg or similar)? Not for general read-write access. You may ask xorriso for the block address of the files' content and use "dd conv=notrunc bs=... seek=... count=... ..." to write new content bytes into it. It is not easily possible to change the file size. More neat would be to repack the ISO from the original ISO and some changed files. Have a nice day :) Thomas
