Hi, Hans wrote: > does anyone know, if there is a limit of the size an iso may have?
With xorriso: 4 TiB = 4096 GiB. An ISO 9660 filesystem may have 2 exp 32 data blocks. The usual block size is 2 exp 11 = 2048 bytes. That would be 2 exp 43 = 8 TiB in total. But xorriso uses libburn for writing and a poor design decision of about 20 years ago lets it use signed int for block addresses. So only 2 exp 31 blocks = 4 TiB are possible with libburn and xorriso. > Background: I have a selfmade lifefile iso image, which was created by > bootcdwrite. The size of the imagefile is about 32GB. Looks like bootcd uses genisoimage for producing the ISO, (https://tracker.debian.org/media/packages/b/bootcd/control-6.7) Anyways, 32 GB of size should not be a problem. > When the stick is booting, first appear the usual text messages, Can you determine the origin of the last visible messages ? BIOS/EFI ? Boot loader (GRUB or ISOLINUX/SYSLINUX) ? Linux ? Debian installation software ? > but then the screen goes blank and the further boot hangs. > However, when I am booting this file (this iso-image) with Virtualbox, > everything is working well. Is Virtualbox using the same BIOS type as the real machine ? I mean EFI versus Legacy BIOS aka CSM mode. > Note: In earlier times I had a smaller image (about 8 GB), which booted > perfectly. Is the USB stick large enough for the image ? Can dd read the whole image back from the USB stick ? # Set variable blocks to image file size divided by 2048 blocks=... # Set variable stick to device file address of the USB stick stick=... dd if="$stick" bs=2048 count="$blocks" | md5sum If no i/o error is reported by dd, compute the MD5 sum of the image file and compare both. > So I believe, the size of the image is, what matters. But maybe I am wrong. It's not impossible. Especially if the stick hardware has problems. But depending on the origin of the last visible message there is also a chance that boot loader or Linux derail because of buggy file content in the elsewise healthy ISO. Have a nice day :) Thomas
