Re: USB Install Fails, Complains about CD-ROM

[Mike Kupfer <mkupfer@alum.berkeley.edu>]

Thomas Schmitt wrote:

> Mike Kupfer wrote:
> > If I plug the stick into the laptop when it's running, the stick is
> > mounted okay. [...] didn't notice anything odd, but then I'm not familiar
> > with the contents of a hybrid image ISO.
> 
> They have about the best verification support you can wish for.
> 
>   https://www.debian.org/CD/faq/#verify
> proposes to learn the number of sectors
> 
>   /sbin/isosize -x <device> 
> 
> and to then compute the checksum of that amount of data
> 
>   dd if=<device> count=<sector count> bs=2048 | sha512sum 
> 
> which is to be compared with the .iso image's line in file SHA512SUMS
> from where you downloaded the ISO.

Hmm.  I used sha256sum instead of sha512sum, but I otherwise followed
the above instructions.  The checksum from the dd pipeline does not
match the checksum of the original .iso file.

It does, however, match the checksum of the first partition.  That is,

  isosize -x /dev/sdb

gives me a sector count of 950976 and a block size of 2048.  And

  dd if=/dev/sdb count=950976 bs=2048 | sha256sum

gives me the same result as

  sha256sum /dev/sdb1

mike