HDIO_SET_DMA failed: Operation not permitted

[Rick Stevens]

On Fri, 2006-01-27 at 16:42 -0800, Biswajit Nayak wrote:
> Hi Experts, 
>    I want to enable the DMA on my linux server. I got
> the following error "HDIO_SET_DMA failed: Operation
> not permitted ". Any take on this ? 
> 
>  [root at localhost ocsperf]# /sbin/hdparm -d1 /dev/hda
> 
> /dev/hda:
>  setting using_dma to 1 (on)
>  HDIO_SET_DMA failed: Operation not permitted
>  using_dma    =  0 (off)
> [root at localhost ocsperf]#

Did you boot the system with "nodma" set?  Check the output of
"cat /proc/cmdline" to see.  If you did, you'll have to reboot the
system WITHOUT that option.

It's also possible that your controller (or drive) doesn't permit DMA.

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- Rick Stevens, Senior Systems Engineer     rstevens at vitalstream.com -
- VitalStream, Inc.                       http://www.vitalstream.com -
-                                                                    -
-   "Do you suffer from long-term memory loss?"  "I don't remember"  -
-                            -- Chumbawumba, "Amnesia" (TubThumping) -
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