Re: Problems when writing DVDs with growisofs

[Rob Bogus <rob23@tmr.com>]

Volker Kuhlmann wrote:

> > I did a blockdev --setra 8 /dev/hdd as root ( 8*512 byte = 4k ).
> >
> > Unfortunately the problem remains the same.
> >    
>
> It is necesssary to first test whether you're running into said kernel
> bug, before considering other possibilities. For this, you will need to
> set read-ahead to zero, not something small.
>
> hdparm -a0 /dev/hdd
>
> will do it. So might blockdev. Check with hdparm /dev/hdd
>  
AFAIK different layers. hdparm works on the drive, blockdev may work in 
the o/s, since I can ret readahead far larger than the drive claims to 
support. And I believe on CD/DVD blockdev is sufficient, it works for me 
when verifying copies.

However, by all means set or check it both ways, I haven't waded through 
the code.

> Note this will make your DVD drive very slow. It is sufficient to
> disable read-ahead from another shell while your reading is going on, as
> long as you make sure that you do it well before the kernel reads near
> the end of the recording.
>
>  
>
> > What next ?
> >    
>
> Provide missing info ;)
>
> Volker
>
>  


--
E. Robert Bogusta
 It seemed like a good idea at the time