Web lists-archives.com

Re: DD bs=4M option on USB mem-stick creates false format

David Christensen:
> uname -a
>Always start a new thread with these:

2017-03-26 19:50:42 dpchrist@jesse ~
$ cat /etc/debian_version
$ uname -a
Linux debian9 4.9.0-2-amd64 #1 SMP Debian 4.9.13-1 (2017-02-27) x86_64

>Also, please post the URL for image.iso/Rescatux 4.0beta.


>Did you checksum your download?  If not, checksum it.  If the download
>checksum is bad, download and checksum again until you get a good
>checksum.  For example:

$ md5sum -c rescatux-0.40b11.iso.md5
rescatux-0.40b11.iso: OK

>In this case, it's 2^20.  Do the burn with 'bs=1M'.  Also, run 'sync'
>after 'dd' to ensure that the command prompt is not returned until all
>the bytes have been written:

Yes, all this was done, the image on the stick is fine and functional!
I did not say there was a problem with it, but the rest of the unused
space ob the disk/mem-stick

>Understand that many memstick images change once they have been
>booted, so you must checksum them immediately after burning.
>(Thankfully, debian-8.7.1-i386-xfce-CD-1.iso doesn't, so I can verify
>my USB flash drive at any time.)

I have done this 3 times bs=4M bs=1M and without a bs= tag, no difference!

>Once you are confident your USB flash drive has a good image, try
>booting it in your newest x86 computer.  If that fails, try other x86
>computers.  If none of them boot, contact your vendor.

No, the image works, it has a problem bringing up the full graphical
part on a an old pc with very little RAM and video memory on its 586
option (it has both a 64 and 32b live parts) and are both jessie based.
The debian 32bit 8,7,1 works fine on the sane machine

>If the USB flash drive boots correctly in newer computers, it is
>probably in "isohybrid" format -- meaning, it's supposed to boot when
>burned to optical media (CD-R, DVD-R, BD-R) and it's supposed to boot
>when burned to a USB drive.  I have found that this "one size fits
>most" approach doesn't boot on all computers, especially older
>computers.  If this is the case, possible solutions include:
>1.  Burn the ISO image to optical media and boot that.

Tough luck, the one machine has no such thing, the ill box has its cd
player jammed shut with a CD in it from 13 years ago that plays fine on
live jessie

>2.  Download a memstick.img file that is meant to be burned to a USB
>drive, burn it to a USB drive, and boot that.  (If your vendor doesn't
>offer such, you might need to find a different tool.)

Again the question is not so much at the vendor's magic system but why
would a 0.6G image rent the rest of the disk useless for copying stuff
in and out, which I have done with many live systems.


Have a nice day