On 2026-10-08 04:43, nwe wrote:
On 10/7/26 9:05 PM, mick.crane wrote:
Could this indicate that the image was written to a partition
/dev/sdf1 instead of /dev/sdf ?
According to my notes I did dd it directly to /dev/sdf
I had noticed the EFI partition inside the iso and left it. It booted
without a problem. My assumption, and possibly flawed logic was that
I'm writing this 256MB iso blob to the first 256MB of my usb drive, and
could have potentially used a 256MB usb drive for just that. Therefore
if the iso uses EFI, that must/(can?) be included in the iso. Correct
me if I am wrong.
Digging into this got me thinking, what if dd writing the iso to sdf1
would have made life easier? I faintly recall trying something like
that some time ago and calling it a dead end, I don't remember the
details. I decided to try it right now. No boot device found. Whatever.
I think that was the problem last time. What I have is working good
enough, why spend more time on it.
Thanks, all.
I've been using the linux OS for quite some time but I never really got
a thorough understanding of the basics of it all.
Recently trying to organise backups I "dd" disks to partitions on
another disk and "dd" put them back on another disk. There are issues in
the sizes of the disks and partitions not matching. I didn't know that
you can repartition a disk but as long as the start of the partition is
exactly the same the underlying data remains intact. Then resize2fs will
make available new space, how magical is that?
Was a bit of a pain because have to copy the primal GPT data to the back
of the disk first.
I decided against that way and now made image files instead of copy to a
partition.
Likely you could boot a kernel and the file structure which is on a
random partition. The PC looks at the first block thingies to discover
what to do so you'd need some method to tell it to look at the random
partition for further instructions. I think it is something like
changing where things think is "root", start of filesystem.
What I don't know is if an area of a storage device can be protected
from "just do it" dd. That would explain your partition one but probably
this is something about CD filesystem.
I mention as doing this was like an eye opener regarding what things are
and hopefully didn't say anything wrong.
mick
