[Discuss] Ways to Get New Laptops to Boot a LiveCD

[John Blomfield]

Alan W. Irwin wrote:
> On 2010-01-15 09:48-0800 Steven Kurylo wrote:
>
>> Alan W. Irwin <irwin at beluga.phys.uvic.ca> wrote:
>>>
>>> I don't know whether the trailing garbage is produced on the drive 
>>> by the
>>> burn step or by some issue when reading a burned disk.  But as far 
>>> as I can
>>> tell it makes no practical difference at all (the result mounts without
>>> issues, for example) except in interfering with the md5sum of the 
>>> entire
>>> disk at once unless you use head as above to get rid of the trailing
>>> garbage.
>>
>> Does this happen on various hardware for you?  I don't recall seeing
>> trailing garbage and I've used at least a dozen burners over the (7?)
>> years with cdrecord.
>
>>
>> I just verified it right now with a cd I burnt
>>
>> # md5sum cdrom.iso
>> 5bf476e2fc445b8d06b3c2a6091fe3aa
>> # cat /dev/cdrom |md5sum
>> 5bf476e2fc445b8d06b3c2a6091fe3aa
>
> Thanks, Steven, for that interesting follow-up comment which 
> encouraged me
> to reassess. For the CD written by k3b but which failed the built-in
> checksum test there, I now get the following results.
>
> irwin at raven> cat /dev/cdrom |md5sum
> b87e267742595444df32e06e5da68951  -
> irwin at raven> md5sum debian-testing-i386-netinst.iso
> b87e267742595444df32e06e5da68951  debian-testing-i386-netinst.iso
>
> So that is perfect agreement with no trailing garbage issues at all.
>
> I incorrectly assumed (at the time and in my subsequent post to VLUG) 
> it was
> trailing garbage that made k3b issue the failed check message because 
> that
> issue has hurt me in the past with a different burner (when using 
> cdrecord
> rather than k3b to burn the CD) and older kernel.
>
> So I am left wondering what caused k3b to issue the incorrect failed 
> check
> message?  This was actually my first use of k3b, and I was most 
> impressed by
> how easy that GUI made it to burn and check CD's.  (Yes, John, I do 
> attempt
> to use GUIs sometimes.... :-) )
I tend mostly to use k3b but the verify has always fails which is why I 
use my little script to check the burn.

John
>
> __________________________
> Alan W. Irwin
>
> Astronomical research affiliation with Department of Physics and 
> Astronomy,
> University of Victoria (astrowww.phys.uvic.ca).
>
> Programming affiliations with the FreeEOS equation-of-state 
> implementation
> for stellar interiors (freeeos.sf.net); PLplot scientific plotting 
> software
> package (plplot.org); the libLASi project (unifont.org/lasi); the 
> Loads of
> Linux Links project (loll.sf.net); and the Linux Brochure Project
> (lbproject.sf.net).
> __________________________
>
> Linux-powered Science
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