getting to 4K disk blocks in ZFS

[Steven Hartland]

----- Original Message ----- 
From: "Mike Tancsa" <mike at sentex.net>
To: "Steven Hartland" <killing at multiplay.co.uk>; "Willem Jan Withagen" <wjw at digiware.nl>; "Peter Wemm" <peter at wemm.org>; 
<freebsd-stable at freebsd.org>
Cc: "Andriy Gapon" <avg at freebsd.org>; "Aristedes Maniatis" <ari at ish.com.au>
Sent: Friday, September 12, 2014 6:23 PM
Subject: Re: getting to 4K disk blocks in ZFS


> On 9/12/2014 4:17 AM, Steven Hartland wrote:
>>>
>>> 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
>>
>> LMK the ident strings and I'll look to update the quirks tables.
>
> How does it work for controllers like mfi ?  The disks come up as mfisyspd#
>
> They are supposedly 4K drives (when attached to ada). If I set vfs.zfs.min_auto_ashift=12 will it "fix" the problem ?
>
> === START OF INFORMATION SECTION ===
> Model Family:     Samsung based SSDs
> Device Model:     Samsung SSD 840 PRO Series
> Serial Number:    S1ANNSAF225154J
> LU WWN Device Id: 5 002538 5a01d79fd
> Firmware Version: DXM05B0Q
> User Capacity:    128,035,676,160 bytes [128 GB]
> Sector Size:      512 bytes logical/physical
> Rotation Rate:    Solid State Device
> Device is:        In smartctl database [for details use: -P show]
> ATA Version is:   ACS-2, ATA8-ACS T13/1699-D revision 4c
> SATA Version is:  SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
> Local Time is:    Fri Sep 12 09:17:42 2014 EDT
> SMART support is: Available - device has SMART capability.
> SMART support is: Enabled
>  # mfiutil show drives
> mfi0 Physical Drives:
>  8 (  119G) JBOD <Samsung SSD 840 5B0Q serial=S1ANNSAF225154J> SATA E1:S1
>  9 (  119G) JBOD <Samsung SSD 840 5B0Q serial=S1ANNSAF225153X> SATA E1:S0
> 10 (  119G) JBOD <Samsung SSD 840 5B0Q serial=S1ANNSAF225159P> SATA E1:S3
> 11 (  119G) JBOD <Samsung SSD 840 5B0Q serial=S1ANNSAF225160E> SATA E1:S2

Quirks are only valid for CAM supported drivers, any RAID which don't use
CAM will bypass this. If you set min_auto_ashift=12 you will ensure that
new pools created will use a min of 4k blocks.

    Regards
    Steve