[CLUE-Tech] RH 7.2 DMA Woes

[Ed Hill]

Jeremiah Stanley wrote:

>>As I recall, with RH 7.1 dma was enabled for installation, which was
>>not the usual practice of other vendors at the time. This led to
>>problems, especially on Toshiba laptops, and RH published an article
>>with a fix of passing the installation program a switch to turn off
>>dma.
>>
> 
> Well, I kept playing with it (helped a friend get it on his new laptop).
> And eventually it started working for me flawlessly. The only difference
> in what I did? I checked for bad blocks on the disks and it never locked
> up again. Which that isn't a solution, but more a mystery... I guess it
> was just a full moon AND halloween at the same time. :)



Ok, DMA is a basically mini-processor that fetches bytes off a device
(here, disk) and so frees up the CPU.  The Linux implimentation works
on *most* chipsets but there have been problems with some laptops,
recent VIA southbridges, etc...  Usually, the problems with a particular
chipset get sorted out quickly, but new chipsets keep appearing!  ;-)

You can set/unset DMA at runtime with "/sbin/hdparm" and the kernel
parameters for DMA on IDE are described in:

   /usr/src/linux-$VER/Documentation/ide.txt



> And, GRUB rocks for those of you who haven't tried it!

Yes, I like it, too!

Ed




-- 
Edward H. Hill III, PhD
Post-Doctoral Researcher    |  Emails:   <ed at eh3.com>, <ehill at mines.edu>
Division of ESE             |  URL:      http://www.eh3.com
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