PATA-disk named sda

PATA-disk named sda

[Christoph Pleger]

Hello,

In the newest Ubuntu Release, my PATA-disk is called sda instead of hda.
Is that a general feature in newer kernel versions or is it a special
feature in Ubuntu?

Regards
  Christoph 

Re: PATA-disk named sda

[Suren Karapetyan]

On Friday 06 July 2007 13:21:32 Christoph Pleger wrote:
> Hello,
>
> In the newest Ubuntu Release, my PATA-disk is called sda instead of hda.
> Is that a general feature in newer kernel versions or is it a special
> feature in Ubuntu?
>
> Regards
>   Christoph
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
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In recent kernels both PATA and SATA (SCSI too) drives are handled by libata 
library. It calls all the drives sd* . 
More info: http://linux-ata.org/

Re: PATA-disk named sda

[Christoph Pleger]

Hello,

> In recent kernels both PATA and SATA (SCSI too) drives are handled by
> libata  library. It calls all the drives sd* . 

If so, what about the use of hdparm then? I could not change parameters
like DMA, MultSectIO and 32-Bit support with hdparm. sdparm also did not
do that work.

Regards
  Christoph  

Re: PATA-disk named sda

[Suren Karapetyan]

On Friday 06 July 2007 14:36:18 Christoph Pleger wrote:
> Hello,
>
> > In recent kernels both PATA and SATA (SCSI too) drives are handled by
> > libata  library. It calls all the drives sd* .
>
> If so, what about the use of hdparm then? I could not change parameters
> like DMA, MultSectIO and 32-Bit support with hdparm. sdparm also did not
> do that work.
>
> Regards
>   Christoph
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

There was a discussion about this on 
http://www.redhat.com/archives/fedora-devel-list/2007-April/msg01079.html
Which concludes with what Alan Cox wrote.
"In DMA modes the 32bit I/O feature and multi-sector mode are not used. For
the moment libata also only supports 32bit PIO on some controllers and for 
those
it si handled automatically. Over time it may well gain 32bit support for 
more,
but again the goal is it will be entirely automatically done if so."

Re: PATA-disk named sda

[Mark Lord]

Christoph Pleger wrote:
> Hello,
> 
>> In recent kernels both PATA and SATA (SCSI too) drives are handled by
>> libata  library. It calls all the drives sd* . 
> 
> If so, what about the use of hdparm then? I could not change parameters
> like DMA, MultSectIO and 32-Bit support with hdparm. sdparm also did not
> do that work.

hdparm will still work for most functions,
but setting dma, multsectio, and 32-bit are now solely
the responsibility of the kernel (libata), for now.

Cheers

Re: PATA-disk named sda

[Jan Engelhardt]

On Jul 6 2007 13:55, Mark Lord wrote:
> Christoph Pleger wrote:
>> Hello,
>> 
>> > In recent kernels both PATA and SATA (SCSI too) drives are handled by
>> > libata  library. It calls all the drives sd* . 
>> 
>> If so, what about the use of hdparm then? I could not change parameters
>> like DMA, MultSectIO and 32-Bit support with hdparm. sdparm also did not
>> do that work.
>
> hdparm will still work for most functions,
> but setting dma, multsectio, and 32-bit are now solely
> the responsibility of the kernel (libata), for now.

Yeah. `smartctl -d ata -a /dev/sda` is also one to work :)



	Jan
-- 

Re: PATA-disk named sda

[Alejandro Riveira Fernández]

El Fri, 6 Jul 2007 10:21:32 +0200
Christoph Pleger <Christoph.Pleger@cs.uni-dortmund.de> escribió:

> Hello,
> 
> In the newest Ubuntu Release, my PATA-disk is called sda instead of hda.
> Is that a general feature in newer kernel versions or is it a special
> feature in Ubuntu?

 You can get information here https://wiki.ubuntu.com/LibAtaForAtaDisks

> 
> Regards
>   Christoph 
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/


-- 
Nunca discutas con un idiota. Al final te hacen rebajarte a su nivel y entonces
te acaban ganando debido a su mayor experiencia.

Re: PATA-disk named sda

[Uwe Kiewel]

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Hash: SHA1

Christoph Pleger schrieb:
> Hello,
> 
> In the newest Ubuntu Release, my PATA-disk is called sda instead of hda.
> Is that a general feature in newer kernel versions or is it a special
> feature in Ubuntu?

IIRC it is relatet to a new libata2 library. My Fedora 7 shows the same
behavior.

Regrads,
Uwe
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Re: PATA-disk named sda

[Alan Cox]

On Fri, 6 Jul 2007 10:21:32 +0200
Christoph Pleger <Christoph.Pleger@cs.uni-dortmund.de> wrote:

> Hello,
> 
> In the newest Ubuntu Release, my PATA-disk is called sda instead of hda.
> Is that a general feature in newer kernel versions or is it a special
> feature in Ubuntu?

General. SATA and now PATA drives map onto the /dev/sd range as do SCSI,
USB etc

Re: PATA-disk named sda

[Christoph Pleger]

Hello,

> > In the newest Ubuntu Release, my PATA-disk is called sda instead of
> > hda. Is that a general feature in newer kernel versions or is it a
> > special feature in Ubuntu?
> 
> General. SATA and now PATA drives map onto the /dev/sd range as do
> SCSI, USB etc

It seems to be not that simple, at least not if both the old IDE
interface and the new libata interface are enabled as modules: In my
Ubuntu system, I created two kernel packages (from the same kernel
source and with the same configuration) and installed them. Afterwards,
I re-created the initial ramdisks, one with the Ubuntu feisty utilities
and one with Debian etch utilities. So, I had the same kernel with
different ramdisks. With the Ubuntu ramdisk, my harddrive was named sda,
but with the Debian ramdisk, it was named hda.

So, the name of the drive can depend on something which happens in the
ramdisk environment. Does anybody know what that is? And is there a
kernel command line parameter which restores the old behaviour?

And what about hdparm (setting 32bit I/O and multi-sector mode)? Suren
wrote that 32bit I/O makes no sense when using DMA. Maybe that's right,
but it does not correspond with my experiences. At least, I have the
"feeling" that my IDE disks work much faster since I enabled 32bit
support (DMA already was on before).

Regards
  Christoph

Re: PATA-disk named sda

[Gabriel C]

Christoph Pleger wrote:
> Hello,
>   

Hi,

>   
>>> In the newest Ubuntu Release, my PATA-disk is called sda instead of
>>> hda. Is that a general feature in newer kernel versions or is it a
>>> special feature in Ubuntu?
>>>       
>> General. SATA and now PATA drives map onto the /dev/sd range as do
>> SCSI, USB etc
>>     
>
> It seems to be not that simple, at least not if both the old IDE
> interface and the new libata interface are enabled as modules: In my
> Ubuntu system, I created two kernel packages (from the same kernel
> source and with the same configuration) and installed them. Afterwards,
> I re-created the initial ramdisks, one with the Ubuntu feisty utilities
> and one with Debian etch utilities. So, I had the same kernel with
> different ramdisks. With the Ubuntu ramdisk, my harddrive was named sda,
> but with the Debian ramdisk, it was named hda.
>
> So, the name of the drive can depend on something which happens in the
> ramdisk environment. Does anybody know what that is? And is there a
> kernel command line parameter which restores the old behaviour?
>   

The boot options are different depending on the distribution you are using.
Every distribution has his own magic for this kind things. ( Debian and 
Ubuntu should have a man page with boot parameters )

On kernels with both IDE and PATA enabled as modules , depends on what 
you load first / include in your initramfs.
If you load the IDE subsystem first you get HD*'s while with PATA you 
get SD*'s.

I don't use Debian nor Ubuntu but it looks like Ubuntu has PATA as 
default while Debian has IDE.

> Regards
>   Christoph
>   

Gabriel

Re: PATA-disk named sda

[Alan Cox]

> So, the name of the drive can depend on something which happens in the
> ramdisk environment. Does anybody know what that is? And is there a
> kernel command line parameter which restores the old behaviour?

Old IDE -> /dev/hd*
LibATA -> /dev/sd*

so if you build both sets of modules it depends who gets loaded first.

> And what about hdparm (setting 32bit I/O and multi-sector mode)? Suren
> wrote that 32bit I/O makes no sense when using DMA. Maybe that's right,
> but it does not correspond with my experiences. At least, I have the
> "feeling" that my IDE disks work much faster since I enabled 32bit
> support (DMA already was on before).

32bit I/O and multi-sector I/O are PIO specific features - they have no
effect on DMA performance. 32bit is on my todo list but very low priority
as for most systems it makes almost no difference.

Alan

Re: PATA-disk named sda

[Rene Herman]

On 07/06/2007 02:30 PM, Christoph Pleger wrote:

> And what about hdparm (setting 32bit I/O and multi-sector mode)? Suren 
> wrote that 32bit I/O makes no sense when using DMA. Maybe that's right, 
> but it does not correspond with my experiences. At least, I have the 
> "feeling" that my IDE disks work much faster since I enabled 32bit 
> support (DMA already was on before).

hdparm -t /dev/hda (or /dev/sda -- it works for the SD interface as well) is 
a quick test of a drive's sequential read speed.

I have, at the time, noticed at least on older controllers/drives (Intel 430 
generation chipsets with things like 8G UDMA33 disks) that I could reliably 
increase the result with something like 1MB/s (to a total of 6 to 8, so it 
wasn't insignificant) by enabling 32-bit I/O. Had also understood that it 
shouldn't make a difference with DMA, but just went "oh well" and stuck a 
"hdparm -c1" in my bootup scripts.

(if anyone tries; note that hdparm -a can have a large effect on that result 
as well on some setups -- on machines where it does, -a 1024 usually gives 
me best results)

Rene.

Re: PATA-disk named sda

[Robert Hancock]

Christoph Pleger wrote:
> Hello,
> 
>>> In the newest Ubuntu Release, my PATA-disk is called sda instead of
>>> hda. Is that a general feature in newer kernel versions or is it a
>>> special feature in Ubuntu?
>> General. SATA and now PATA drives map onto the /dev/sd range as do
>> SCSI, USB etc
> 
> It seems to be not that simple, at least not if both the old IDE
> interface and the new libata interface are enabled as modules: In my
> Ubuntu system, I created two kernel packages (from the same kernel
> source and with the same configuration) and installed them. Afterwards,
> I re-created the initial ramdisks, one with the Ubuntu feisty utilities
> and one with Debian etch utilities. So, I had the same kernel with
> different ramdisks. With the Ubuntu ramdisk, my harddrive was named sda,
> but with the Debian ramdisk, it was named hda.
> 
> So, the name of the drive can depend on something which happens in the
> ramdisk environment. Does anybody know what that is? And is there a
> kernel command line parameter which restores the old behaviour?
> 
> And what about hdparm (setting 32bit I/O and multi-sector mode)? Suren
> wrote that 32bit I/O makes no sense when using DMA. Maybe that's right,
> but it does not correspond with my experiences. At least, I have the
> "feeling" that my IDE disks work much faster since I enabled 32bit
> support (DMA already was on before).

No, it has absolutely no effect in DMA mode.

Currently the DMA, multi-sector mode, etc. are not controllable with 
hdparm with libata. libata is designed to use the fastest settings 
possible by default. In a lot of cases this messing with hdparm was only 
needed because of stupidity with the old IDE code (like DMA not being 
automatically enabled if the low-level driver was built modular).

-- 
Robert Hancock      Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/

Re: PATA-disk named sda

[Mark Lord]

Robert Hancock wrote:
>..
> Currently the DMA, multi-sector mode, etc. are not controllable with 
> hdparm with libata. libata is designed to use the fastest settings 
> possible by default. In a lot of cases this messing with hdparm was only 
> needed because of stupidity with the old IDE code (like DMA not being 
> automatically enabled if the low-level driver was built modular).

Actually, most of the hdparm flags were put there to help test the IDE
subsystem and to help debug the much stranger hardware it had to deal with.

"DMA off by default" was a Linus Torvalds request, to help ensure data safety
with all of the weird and wonderful crap pre-standardization.

Cheers

Re: PATA-disk named sda

[Bartlomiej Zolnierkiewicz]

On Friday 06 July 2007, Mark Lord wrote:
> Robert Hancock wrote:
> >..
> > Currently the DMA, multi-sector mode, etc. are not controllable with 
> > hdparm with libata. libata is designed to use the fastest settings 
> > possible by default. In a lot of cases this messing with hdparm was only 
> > needed because of stupidity with the old IDE code (like DMA not being 
> > automatically enabled if the low-level driver was built modular).
> 
> Actually, most of the hdparm flags were put there to help test the IDE
> subsystem and to help debug the much stranger hardware it had to deal with.
> 
> "DMA off by default" was a Linus Torvalds request, to help ensure data safety
> with all of the weird and wonderful crap pre-standardization.

Exactly as Mark says.

I just want to add that "DMA off by default" hasn't been a case for a long
time now and since 2.6.21 the config option for "DMA on by default" is also
finally gone (to make a long story short: this was the best way to fix some
bugs while not causing regressions, not to mention that it was defaulting
to Y for years).

Thanks,
Bart

Re: PATA-disk named sda

[Bartlomiej Zolnierkiewicz]

Hi,

On Friday 06 July 2007, Robert Hancock wrote:
> Christoph Pleger wrote:
> > Hello,
> > 
> >>> In the newest Ubuntu Release, my PATA-disk is called sda instead of
> >>> hda. Is that a general feature in newer kernel versions or is it a
> >>> special feature in Ubuntu?
> >> General. SATA and now PATA drives map onto the /dev/sd range as do
> >> SCSI, USB etc
> > 
> > It seems to be not that simple, at least not if both the old IDE
> > interface and the new libata interface are enabled as modules: In my
> > Ubuntu system, I created two kernel packages (from the same kernel
> > source and with the same configuration) and installed them. Afterwards,
> > I re-created the initial ramdisks, one with the Ubuntu feisty utilities
> > and one with Debian etch utilities. So, I had the same kernel with
> > different ramdisks. With the Ubuntu ramdisk, my harddrive was named sda,
> > but with the Debian ramdisk, it was named hda.
> > 
> > So, the name of the drive can depend on something which happens in the
> > ramdisk environment. Does anybody know what that is? And is there a
> > kernel command line parameter which restores the old behaviour?
> > 
> > And what about hdparm (setting 32bit I/O and multi-sector mode)? Suren
> > wrote that 32bit I/O makes no sense when using DMA. Maybe that's right,
> > but it does not correspond with my experiences. At least, I have the
> > "feeling" that my IDE disks work much faster since I enabled 32bit
> > support (DMA already was on before).
> 
> No, it has absolutely no effect in DMA mode.
> 
> Currently the DMA, multi-sector mode, etc. are not controllable with 
> hdparm with libata. libata is designed to use the fastest settings 
> possible by default. In a lot of cases this messing with hdparm was only 
> needed because of stupidity with the old IDE code (like DMA not being 
> automatically enabled if the low-level driver was built modular).

AFAIR there has never been such issue with IDE subsystem.

In modular case you just have to remember to _not_ load generic
IDE host driver if you don't need it, same with libata PATA.

Bart