Re: CDRecord proper dev specification w/2.6.x

[Bill Davidsen <davidsen@tmr.com>]

James Finnall wrote:

> Hello,
>
> Everytime I use cdrecord under Linux 2.6 kernel and reference the drive by 
> the /dev/devid it responds with the following:
>
> Cdrecord 2.00.3 (i686-pc-linux-gnu) Copyright (C) 1995-2002 Jörg Schilling
> TOC Type: 1 = CD-ROM
> scsidev: '/dev/sr0'
> devname: '/dev/sr0'
> scsibus: -2 target: -2 lun: -2
> Warning: Open by 'devname' is unintentional and not supported.
> Linux sg driver version: 3.5.27
>
>
> Under 2.4 series using the generic scsi device name I could use -scanbus to 
> report the devices.  But now it only reports errors with no usable 
> information reported.  In the above output, the scsibus:-2, etc. always 
> remains the same regardless of what device I use.
>
> If I use: "cdrecord dev=ATAPI -scanbus"  then it reports only the two 
> drives I have connected through firewire on scsibus0 and scsibus1.  It 
> doesn't report my PATA drive at all.  On my notebook the internal DVD 
> drive is a PATA drive also and it doesn't report it either.
>
> So then, what is the proper way to discover/designate the drives under the 
> 2.6 kernel without using the generic scsi interface?
>
> Sorry that I am so dense that I am unable understand the man page.
>  
You appear to be running a stock cdrecord version, which complains about 
write by device name, but works. If the message bothers you there are 
modified versions which also will burn DVDs if you have the hardware. I 
won't get into the reasons why this happens, Joerg wants it to work that 
way. You can use ATA or ATAPI, but you don't get rid of the warnings, so 
why bother? Use the /dev/hdX interface for audio burning, it will do DMA 
instead of pio (which eats your CPU).

There still appears to be a bug in the kernel which blocks the "-msinfo" 
option from working as a normal user, regardless of permissions on the 
drive. This is deliberate and makes multi-session a problem.

Short answer, use the /dev/hdX name, it works better. You can make the 
device owned by a group, like burnCD, make yourself a member, and give 
group RW on the device. That makes burning as a user possible except 
multisession.

--
bill davidsen <davidsen@tmr.com>
 CTO TMR Associates, Inc
 Doing interesting things with small computers since 1979