enabling dma using hdparm

[vijirin]

hi all,
I want to enable dma for devices, but i can't. i used hdparm and it is giving the following error....

hdparm -d1 /dev/hdb

/dev/hdb:
 setting using_dma to 1 (on)
 HDIO_SET_DMA failed: Operation not permitted
 using_dma    =  0 (off)

plz help
how could i enable this...
what could be wrong
i am using knoppix 4.02 version
thanks in advance
viji

[cbagger01]

Try:

sudo hdparm -d1 /deb/hdb

The "sudo" command lets you run a command using the Superuser authority, otherwise known in Unix/Linux as the "root" user account.

To open a terminal window with superuser authority, you can type:

sudo su

and you can even create a "root" account password with:

sudo passwd

[vijirin]

i issued the command as a super user, but also the same error

plz help

[marhleet]

are you sure ?
why the hdb ?
do you have a hdb ?
most systems have an hda

mine works with
-d1 and
-d 1

[vijirin]

what is there if it is hda or hdb
my harddisk is connected as primary slave that's why hdb...

anyway in my case its not working....