question about burning and then reading (dd) to confirm sha256sum

[jd1008]

On 04/02/2015 12:44 PM, John Pilkington wrote:
> On 02/04/15 18:13, jd1008 wrote:
>>
>>
>> On 04/02/2015 02:56 AM, John Pilkington wrote:
>>> On 01/04/15 20:18, jd1008 wrote:
>>>> After burning 3 DVD's, and reading them back to compute sha256sum.
>>>> all three of them generated these error messages during readback,
>>>> and all 3 messages show the error was past the 4gb offset.
>>>>
>>>> Is this a media issue or is it the burner?
>>>>
>>>
>>> I burn DVDs from iso images using the k3b verify option, but I don't
>>> think you can separate the two parts.
>>>
>>> After iso creation and before burning I use implantisomd5; checkisomd5
>>> then does what it says.
>>>
>>> For explanation see:
>>>
>>> http://www.g-loaded.eu/2006/10/07/verify-a-burned-cddvd-image-on-linux/
>>>
>>> HTH
>>>
>>> John P
>>>
>> Problem with k3b is that it refuses to force 2X speed.
>
> Do you *want* a slow burn?  I rarely have problems at 8x. Verbatim 
> DVD+R rated at 16x.  But obviously many other factors can cause 
> problems too. And I'm using SL7, el7 near-clone, which is rare here, 
> IIRC.
>
> John
at 2X, the burning is more reliable and produces recordings that are 
more durable.

You do not have to take my word for it.
I know engineers who worked for manufacturers where they
were designing and producing cd/dvd burners.