[lug] Creating DVD for FC5 - trouble burning iso

[D. Stimits]

David L. Anselmi wrote:
> Gordon Golding wrote:
> 
>> I want to burn a DVD for FC5.
>>
>> Things seem to go OK, but the DVD won't boot on 3 different machines
>> (including the one I use to burn it). I've used a borrowed FC5 CD1,
>> and they all boot off that.
> 
> 
> They can boot with a CD but not a DVD?  Are you sure the machines can 
> boot off a DVD?  Are you sure you have the right media for your burner? 
>  All that should work but I haven't paid much attention since DVD 
> recording was painful.
> 
>> Downloaded FC-5-i386-DVD.iso
>> Did sha1sum - it was OK.
> 
> 
> Did you do sha1sum on /dev/dvd after you burned the disk so you know 
> that it burned correctly?
> 
> The various ways I've tried to verify a burn was good have never 
> reported success, even when the CD was good enough.  Since you care 
> about booting you might use dd and just compare the first bit of the DVD 
> to the first bit of the iso.

One thing I've tried is to use dd to create an ISO from the original CD. 
If it's really bad, dd will fail. If it is readable but not correct, 
then the sha1sum of the resulting ISO will show bad. You can often mount 
the ISO though on loopback and maybe figure out whether what remains is 
useful or not. Of the things I tried to burn at home (using cheap blank 
media which is destined for the trash can), I've never managed to create 
one that dd works on *and* it passes sha1sum. Most of the cheap media 
I've tried won't even work without dd failing with read error. I'm not 
sure if there is a difference in buffering and error compensation 
between dd and "normal" other ways of using a cd, like mounting. dd 
seems to be forgiving of filesystem errors, but unforgiving of 
completely non-readable bits on optical media.

D. Stimits, stimits AT comcast DOT net