Re: Detection of Advanced Format drives

From: Arun
Date: Tue Sep 27 2011 - 14:36:22 EST


Mike,

Regarding "Linux does, and will bubble this additional information up
the stack."...

Should I suppose that it is an already available piece of information
to the userland? Or do I need to modify the hdparm/fdisk code to get
this piece of info?

Once again, if this is not the place to ask about
userland/hdpark/fdisk etc. please redirect to the correct location.


Regards,

Arun




On Tue, Sep 27, 2011 at 23:29, Joshua Scoggins
<theoretically.x64@xxxxxxxxx> wrote:
> Didn't know about the physical_block_size field. My AV-25 reports the
> physical_block_size as 4096 and the logical block size as 512.
>
> Thanks for the heads up and sorry about the misinformation. Not my
> intention to spread FUD like that
>
> On Mon, Sep 26, 2011 at 1:09 PM, Mike Snitzer <snitzer@xxxxxxxxx> wrote:
>> On Mon, Sep 26, 2011 at 3:48 PM, Joshua Scoggins
>> <theoretically.x64@xxxxxxxxx> wrote:
>>> Keep in mind that some AF drives will not report their actual sector
>>> sizes. I have this issue with the WD AV-25 series. This is to provide
>>> compatibility with older operating systems that don't support AF
>>> drives. These are called generation 1 devices. Newer drives will
>>> directly report their sector size as 4096 through the drive identify
>>> data older ones will say 512. At that point you just need to do a
>>> google search to see if it's AF or not.
>>
>> Linux should publish the discrepancy with these <disk> specific sysfs files:
>>
>> /sys/block/<disk>/queue/logical_block_size=512
>> /sys/block/<disk>/queue/physical_block_size=4096
>>
>> But are you saying you have an AF disk that doesn't publish this
>> discrepancy via the IDENTIFY DEVICE (ATA) or READ CAPACITY 16 (SCSI)
>> command?
>>
>
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