Problem adding SCSI quirks for a SSD, 4K sector and ZFS

[Borja Marcos]

On Jan 24, 2013, at 12:19 PM, Steven Hartland wrote:

> 
> ----- Original Message ----- From: "Borja Marcos" <borjam at sarenet.es>
> To: <freebsd-scsi at freebsd.org>
> Cc: "FreeBSD Filesystems" <freebsd-fs at freebsd.org>
> Sent: Thursday, January 24, 2013 9:46 AM
> Subject: Problem adding SCSI quirks for a SSD, 4K sector and ZFS
> 
> 
>> 
>> Hello,
>> 
>> Crossposting to FreeBSD-fs, as I am wondering if I have had a problem with ZFS and sector size detection as well.
>> 
>> I am doing tests with an OCZ Vertex 4 connected to a SAS backplane.
>> 
>> < OCZ-VERTEX4 1.5>                 at scbus6 target 22 lun 0 (pass19,da15)
>> 
>> (The blank before "OCZ" really appears there)
>> 
>> pass19: < OCZ-VERTEX4 1.5> Fixed Direct Access SCSI-5 device
>> pass19: Serial Number OCZ-1SVG6KZ2YRMSS8E1
>> pass19: 3.300MB/s transfers
>> 
>> I am bypassing an "aac" RAID card so that the disks are directly attached to the da driver, instead of relying on the so-called JBOD feature.
>> 
>> I have had a weird problem, with the disk being unresponsive to the REQUEST CAPACITY(16) command. Weird, seems it timeouts.
>> 
>> So, just to complete the tests, I have added a quirk to scsi_da.c. Anyway, I also need the disk to be recognized as a 4K sector drive.
>> 

(...)

> Simple answer is ZFS doesn't understand quirks. The attached patch does
> what you're looking for along with a few other things, see notes at
> the top for details.
> 
> Its not a final version as there's still some discussion about
> implementation details but it should do what your looking for.

Oh, sorrry for the confusion! I assumed that the da driver would announce a 4 KB sector instead of the 512 bytes due to the quirks. 

Which  brings an interesting question, I might have a potential time bomb in my experimental machine at home. It's a ZFS mirror with two 500 MB disks. One of the has 512 byte sectors, the other is "advanced format". 





Borja.