Mailinglist Archive: opensuse (5130 mails)

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Re: [SLE] DMA Nightlmare on SuSE 10.x Revisited
  • From: Basil Chupin <blchupin@xxxxxxxxxx>
  • Date: Mon, 29 May 2006 00:35:40 +1000
  • Message-id: <4479B53C.5050009@xxxxxxxxxx>
Carlos E. R. wrote:
Hash: SHA1

The Saturday 2006-05-27 at 13:25 +1000, Basil Chupin wrote:

You can use then:

DEVICES_FORCE_IDE_DMA="/dev/hdb:-c1:-d1-u1 /dev/hdd:-c1:-d1-u1"
Sorry, but this does NOT work :-( .

It certainly does in 9.3: I've been using it for months. I was told about it here, somebody using 10.0. My line is:

DEVICES_FORCE_IDE_DMA="/dev/hda:-c1:-m16:-u1 /dev/hdb:-c1:-m16:-u1 /dev/hdd:-c1:-m16:-u1 /dev/hdc:on"

Yeah, but we are talking here about v10.1 which is an animal of a different kind...

OK, this is what I tried and the results.

Firstly, the comment that the params you show above are not the same as you gave in an earlier response so I'll ignore the above and use what you gave before EXCEPT that you shown above an additional set of " : " after the '-m16' parameter and these " : " were not shown in the earlier response - so, I did a test using both "methods": with and without the extra " : ".


To begin, I cleared /etc/init.d/boot.local. Then I did 2 separate tests by putting into /etc/sysconfig/ide these:

DEVICES_FORCE_IDE_DMA="/dev/hdb:-c1:d1u1 /dev/hdd:-c1:d1u1"
DEVICES_FORCE_IDE_DMA="/dev/hdb:-c1:-d1:-u1 /dev/hdd:-c1:-d1:u1"

and then rebooted after making each entry in ../../ide.

On both occasions the above statements in /ide were ALTERED to read:


In Control Centre (from now referred to simply as CC) /dev/hdb was NOT set to a DMA of any kind but /dev/hdd was correctly set (to Udma/66).

Trying to alter in CC the dma for hdb produced the error message "Cannot set required mode '%1 for device %2' ".

Doing hdparm -I /dev/hdx showed that hdb had a setting of udma2 and hdd had udma4.

Now, rebooting the system at this point(s) resulted in this change in /ide file:


but CC still showed that hdb had no dma set, but hdd was set to udma/66 and hdparm -I still showed the same results as just mentioned.


I then used the approach which Silviu provided which was to use /etc/init.d/boot.local.

I first altered /etc/sysconfig/ide to read


and then inserted in /boot.local

hdparm -d1c1u1 /dev/hdb
hdparm -d1c1u1 /dev/hdd

and rebooted the system.

Now CC is showing correctly that the hdb is set to udma/33 and hdd is set to udma/66 (with hdparm -I still showing that both devices have their udma set). This information is now static after each reboot. The statement in ../ide remains unaltered with DMA="".

In fact, SuSE automatically reformats this statement into-


Use a text editor to directly edit the file.

Doesn't appear that using anything will stop from something in SuSE amending ../ide to whatever it is "programmed" to do (against your will in fact).

All these things above I found after much time in typing/rebooting/typing/rebooting/typing/ad finitum :-) . I'll never be same...


Ignorance can be corrected. Stupidity is permanent.

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