[ILUG] TOTD: Linux/FC and Intel 6300ESB (ICH5) IDE/SATA

[Paul Jakma]

If you have a machine with Intel 6300ESB ICH5 IDE/SATA controller: 
The Linux IDE PIIX driver really sucks on it for some reason. No DMA, 
about 2MB/s + lots of CPU load.

If running a kernel which has IDE built-in, and libata provided as 
modules:

mkinitrd --with=ata_piix /boot/initrd-<version>.img <version>

Then add:

 	ide0=noprobe ide1=noprobe

to the kernel command line arguments (eg by editing 
/boot/grub/grub.conf). Reboot and hey presto you should find that 
Linux IDE does /not/ claim ownership of your ICH5 IDE/SATA 
controllers and hence allows libata's ata_piix to drive it instead 
with full DMA goodness and 50MB/s without CPU being eaten alive doing 
PIO.

NB: If your distribution didn't set up /etc/fstab to mount 
filesystems by fs label, you will need to adjust /etc/fstab. Fedora 
has always setup fstab to mount by label iirc.

regards,
-- 
Paul Jakma	paul at clubi.ie	paul at jakma.org	Key ID: 64A2FF6A
Fortune:
How many surrealists does it take to screw in a lightbulb?

One to hold the giraffe and one to fill the bathtub with brightly colored
power tools.