PE2650 RH7.3 and CD-ROM DMA

Wes Kurdziolek wkurdzio at
Tue Jun 25 12:37:00 CDT 2002

Quoting Darrin Hyrup <shades at>:
> Disabling the DMA via "hdparm -d0 /dev/cdrom" appears to work, however,
> should I need to do that?  I know that most of these machines are tested
> by 
> Dell with the latest OS and kernel releases, so I would assume this 
> configuration would run out of the box.
> If I do need to keep using hdparm, should I use the -k setting as well
> in 
> my startup script?

Red Hat 7.3 should, AFAIK, disable DMA on the CD-ROM drive as part of its
startup procedure. If it's not w/ the new errata kernel, then you should file a
bug report.

The -k switch for hdparm only applies for soft reboots when running hdparm is
*not* part of the normal boot routine. For Red Hat Linux, it is. Check the
/etc/sysconfig/ directory for a file called harddisks or harddrives or something
like that. Copy the file to harddiskhdX or harddrivehdX where X is the drive
letter for your CD-ROM drive. Edit that file, and change the DMA setting to off.
Every time Red Hat boots, it should disable DMA on the CD-ROM drive
automagically (since it's not doing it like it should anyway).

> Thanks,
> Darrin
> _______________________________________________
> Linux-PowerEdge mailing list
> Linux-PowerEdge at
> Please read the FAQ at or search the list
> archives at

Wes Kurdziolek
UNIX Systems Administrator
wkurdzio at

More information about the Linux-PowerEdge mailing list