getting to 4K disk blocks in ZFS

[Justin T. Gibbs]

On Sep 11, 2014, at 5:32 PM, Willem Jan Withagen <wjw at digiware.nl> wrote:

> On 11-9-2014 19:49, Peter Wemm wrote:
>>> Another downside is 1/4th of uberblocks, 32 vs 128.
>>> Also, automatic sector size detection works great for me and I've never had
>>> a need to manually tweak ashift.
>> 
>> Unfortunately, I have.  Same drive connected two different ways:
>> 
>> da12 at mps1 bus 0 scbus1 target 11 lun 0
>> da12: <ATA ST4000VN000-1H41 SC43> Fixed Direct Access SCSI-6 device 
>> da12: 600.000MB/s transfers
>> da12: Command Queueing enabled
>> da12: 3815447MB (7814037168 512 byte sectors: 255H 63S/T 486401C)
>> 
>> ada1 at ahcich1 bus 0 scbus3 target 0 lun 0
>> ada1: <ATA ST4000VN000-1H41 SC43> ATA-8 SATA 3.x device
>> ada1: 600.000MB/s transfers (SATA 3.x, UDMA6, PIO 8192bytes)
>> ada1: Command Queueing enabled
>> ada1: 3815447MB (7814037168 512 byte sectors:  16H 63S/T 16383C)
>> ada1: quirks=0x1<4K>
>> 
>> The 4k flag is missing when it's on the sas controller.  The Ident strings are 
>> changed.
>> 
>> This came up elsewhere recently.
> 
> I reported the same fact for the new set of WD REDs I installed.
> Seems that ada and da have different quirks tables...
> So disks on SATA connectors on the motherboard are diagnosed as being 4Kb.
> The disks on my twa don't get the quirk and are considered 512b
> 
> —WjW

I’m surprised that we have to constantly add quirks.  Are these drives really failing to report their ata params correctly?  Is there a reason we don’t currently utilize the ata params data (which is already fetched for trim/unmap detection) to also set lbppbe (logical block per physical block exponent) and lalba (lowest aligned lba)?  We may find that many of the existing quirks are unnecessary if we fix the probe code.

—
Justin