[CentOS] Setting CDROM parms

Mr. X tlviewer at yahoo.com
Sun Jan 3 04:32:29 UTC 2010

--- On Sat, 1/2/10, Robert <kerplop at sbcglobal.net> wrote:

> From: Robert <kerplop at sbcglobal.net>
> Subject: [CentOS] Setting CDROM parms
> To: "CentOS mailing list" <centos at centos.org>
> Date: Saturday, January 2, 2010, 6:23 PM
> My apologies in advance for asking
> such an elementary question.  I 
> called myself searching the Installation Guide and
> Deployment Guide, 
> with no success.
> The situation is that I bought a Lite-On ATAPI iHAP122 that
> will not 
> burn DVDs unless I use hdparm to turn dma off. I bought
> that drive 
> because it was a rare beige drive.  Until I can find a
> decent DVD burner 
> and/or get a Windows machine put together strictly for
> doing BIOS 
> updates, running with dma disabled seems to be the best
> solution. 
> (hdparm -d0 /dev/hdb )
> So, my question is, where should I script the command
> without having to 
> become root each time I wat to burn a DVD?


The -k flag to hdparm allows you to persist your settings across a reset.
Did you try to elevate the dma to the highest supported by the device?
--------------------- info ------------
sudo hdparm -I /dev/cdrom


ATAPI CD-ROM, with removable media
        Model Number:       Slimtype DVDRW SOSW-852S
        Serial Number:
        Firmware Revision:  PSU2
        Supported: CD-ROM ATAPI-2
        DRQ response: 50us.
        Packet size: 12 bytes
        LBA, IORDY(cannot be disabled)
        DMA: mdma0 mdma1 mdma2 udma0 udma1 *udma2
             Cycle time: min=120ns recommended=120ns
        PIO: pio0 pio1 pio2 pio3 pio4
             Cycle time: no flow control=227ns  IORDY flow control=120ns
--------------- end snip --------------

On Centos, you can run k3b to handle burning easily. The only caveat is
sometimes on KDE installs you will have the hdc unavailable for exclusive access. You can fix that by 
$sudo killall kio_audiocd

see http://bugs.kde.org/135669

One more thing. If you want to demo the Knoppix 6, save burning the DVD and boot the ISO directly with qemu-kvm or qemu with kqemu.

>sudo qemu -kernel-kqemu -cdrom KNOPPIX_V6.0.1CD-2009-02-08-EN.iso -m 384 -usb -boot d -net nic,model=rtl8139 -net user &

put the above on one line. You need 2 packages to run qemu in this fast mode. 

$ rpm -qa | grep qemu



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