To fix this, you just copy /etc/sysconfig/harddisks to /etc/sysconfig/harddiskhda and change settings there. If you have several drives, copy the file to /etc/sysconfig/harddiskhdx where x is the letter of the device you want to change the settings on.

In my system I have 2 hard disks, a DVD-ROM, and CD-RW drive. My hard disks are hda and hdb, my DVD-ROM is hdc, and my CD-RW drive is hdd. I need different settings for all devices, so I have 4 files that set each device up individually, instead of the harddisks file. The files I have are obviously harddiskhda, harddiskhdb, harddiskhdc, and harddiskhdd. I still got harddisks, but that has no effect seeing as all my drives have individual configs.

For my hard disks, hda and hdb, they are configured just as if I typed hdparm -c1 -d1 -m16 -X69 /dev/hda or hdb, depending on the drive. Both drives are identical, so can use the same settings.

Another performance boost can be gained for your optical drives by passing kernel parameters at boot time. I use hdc=ide-scsi and hdd=ide-scsi at the moment. I will be experimenting to see if performance is improved on my hard disks as well. I'll let you know if it works as expected...