2009-12-11 07:15:50

by James Andrewartha

[permalink] [raw]
Subject: Re: ATA support for 4k sector size

Martin K. Petersen wrote:
>>>>>> "Matthew" == Matthew Wilcox <[email protected]> writes:
>
> Matthew> Lowest aligned logical block address=0
>
> Matthew> This disagrees with Martin's assertion.
>
> The original roadmap was to transition to 4KB sectors in 2006,
> coinciding with the Vista release.
>
> Given how long this has taken (we're now talking ~2011 for GA) it may
> very well be that the alignment knobs will be unused because everybody
> will be using Vista or 7 by then.

The plan does seem to have changed - WD's shipping 4k sector drives that are
sane and require a drive jumper or tool for WinXP and old cloning utilities.

http://techreport.com/discussions.x/18115
http://wdc.com/en/products/advancedformat/
http://www.wdc.com/wdproducts/library/whitepapers/en/2579-771430-A00.pdf

--
James Andrewartha


2009-12-11 07:27:05

by H. Peter Anvin

[permalink] [raw]
Subject: Re: ATA support for 4k sector size

On 12/10/2009 11:05 PM, James Andrewartha wrote:
> Martin K. Petersen wrote:
>>>>>>> "Matthew" == Matthew Wilcox <[email protected]> writes:
>>
>> Matthew> Lowest aligned logical block address=0
>>
>> Matthew> This disagrees with Martin's assertion.
>>
>> The original roadmap was to transition to 4KB sectors in 2006,
>> coinciding with the Vista release.
>>
>> Given how long this has taken (we're now talking ~2011 for GA) it may
>> very well be that the alignment knobs will be unused because everybody
>> will be using Vista or 7 by then.
>
> The plan does seem to have changed - WD's shipping 4k sector drives that
> are sane and require a drive jumper or tool for WinXP and old cloning
> utilities.
>
> http://techreport.com/discussions.x/18115
> http://wdc.com/en/products/advancedformat/
> http://www.wdc.com/wdproducts/library/whitepapers/en/2579-771430-A00.pdf
>

Even more important, the alignment can be changed as opposed to being
fixed for the manufacture of the disk.

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.

2009-12-11 07:33:53

by Martin K. Petersen

[permalink] [raw]
Subject: Re: ATA support for 4k sector size

>>>>> "James" == James Andrewartha <[email protected]> writes:

>> Given how long this has taken (we're now talking ~2011 for GA) it may
>> very well be that the alignment knobs will be unused because
>> everybody will be using Vista or 7 by then.

James> The plan does seem to have changed - WD's shipping 4k sector
James> drives that are sane and require a drive jumper or tool for WinXP
James> and old cloning utilities.

The disk vendors have agreed to transition no later than 2011. There
are definitely drives coming out with 4KB physical blocks before then.

There has been a lot of discussion of the merits of shipping 1-aligned
drives by default given that Vista and Windows 7 handle alignment
correctly.

I don't think there has been any firm decisions in IDEMA wrt. 0
vs. 1-aligned. It may be up to each vendor's discretion, target market
segment, etc.

--
Martin K. Petersen Oracle Linux Engineering