Enabling DMA for DVD drive.

morghanphoenix · 09-17-2006, 12:14 AM

Wondering if both devices on the secondary IDE cable need to support DMA because my CD writer doesn't. I ran a script that was supposed to enable DMA and got a message saying it was unable to, but not why. So if both don't need to be able to use DMA could someone post the terminal commands to enable it.

macemoneta · 09-17-2006, 11:18 AM

The command to enable DMA is:

hdparm -d1 /dev/hdX

Where '/dev/hdX' is the drive (for example, /dev/hda, /dev/hdc, etc.).

Check your BIOS settings for the drive, some BIOS have the option to enable/disable DMA. Also, make sure the drives are properly jumpered master/slave, as the 'cable select' setting can confuse some controllers.

morghanphoenix · 09-17-2006, 11:57 PM

I allready knew how to do all the hardware and bios settings, it just wouldn't work on the command line. I put in the command you told me and got "permission denied", tried it again with sudo before it and it worked perfectly. Got any ideas why when I type su and enter my password it says "authentication failure", it is the root password, no idea why it won't let me do su but sudo works with the same password. Anyways, thanks for the command, DMA enabled and working greaat.

HappyTux · 09-18-2006, 01:07 AM

Quote:

Originally Posted by morghanphoenix

I allready knew how to do all the hardware and bios settings, it just wouldn't work on the command line. I put in the command you told me and got "permission denied", tried it again with sudo before it and it worked perfectly. Got any ideas why when I type su and enter my password it says "authentication failure", it is the root password, no idea why it won't let me do su but sudo works with the same password. Anyways, thanks for the command, DMA enabled and working greaat.

You su problem most likely has to do with root being disabled in Ubuntu. Have you checked their wiki for instructions on creating a real root account? For the hdparm command if you want it to be set on boot edit the /etc/hdparm.conf file to look similar to this at the bottom.

Code:

/dev/hdc {
        dma = on
}

Changing the /dev/hdc to your drive letter of course.

archtoad6 · 10-22-2006, 02:31 PM

Code:

sudo su

should still work.

Also, I believe it's your own password that is needed in a sudo situation, even if you have set up that root acct. ... (If I have got this wrong, some regular *buntu user please correct me.)

sleepindawg · 10-22-2006, 06:21 PM

I believe that the first user on Ubuntu has sudo rights "without" having to enter a password. The first user created during install is like a "superuser" I do believe, therefor not having to use the password. Yes, using "su" as superuser will need the superuser's password.

binary_y2k2 · 10-22-2006, 09:10 PM

Quote:

Originally Posted by sleepindawg

I believe that the first user on Ubuntu has sudo rights "without" having to enter a password. The first user created during install is like a "superuser" I do believe, therefor not having to use the password. Yes, using "su" as superuser will need the superuser's password.

No the first user setup still has to enter a password to use sudo, it's only different on the liveCD where sudo doesn't need the password. You can set a user to be able to use sudo without a password, but it's not set that way by default.