Attempting ATA TRIM on SAS devices?

[Steven Hartland]

----- Original Message ----- 
From: "Garrett Wollman" <wollman at csail.mit.edu>
To: "Steven Hartland" <killing at multiplay.co.uk>
Cc: <freebsd-scsi at freebsd.org>
Sent: Wednesday, January 08, 2014 8:48 PM
Subject: Re: Attempting ATA TRIM on SAS devices?


> <<On Wed, 8 Jan 2014 20:36:13 -0000, "Steven Hartland" <killing at multiplay.co.uk> said:
> 
>> It should only do this if your drive reports it supports
>> ATA_TRIM by setting the ATA_SUPPORT_DSM_TRIM bit in the
>> response to an ATA_IDENTIFY command sent to it using ATA
>> passthrough.
> 
>> What does the following report:
>> camcontrol identify da12
> 
> It says:
> 
> pass13: <TALOS2 2.25> ATA-8 SATA 3.x device
> pass13: 600.000MB/s transfers, Command Queueing Enabled
> 
> protocol              ATA/ATAPI-8 SATA 3.x
> device model          TALOS2
> firmware revision     2.25
> serial number         A179E011337000251
> WWN                   5e83a97a101b6024
> cylinders             16383
> heads                 16
> sectors/track         63
> sector size           logical 512, physical 512, offset 0
> LBA supported         468883199 sectors
> LBA48 supported       468883199 sectors
> PIO supported         PIO4
> DMA supported         WDMA2 UDMA6 
> media RPM             non-rotating
> 
> Feature                      Support  Enabled   Value           Vendor
> read ahead                     yes      no
> write cache                    yes      no
> flush cache                    yes      yes
> overlap                        no
> Tagged Command Queuing (TCQ)   no       no
> Native Command Queuing (NCQ)   yes              32 tags
> SMART                          yes      yes
> microcode download             yes      yes
> security                       yes      no
> power management               yes      yes
> advanced power management      yes      yes     254/0xFE
> automatic acoustic management  no       no
> media status notification      no       no
> power-up in Standby            yes      no
> write-read-verify              yes      no      0/0x0
> unload                         yes      yes
> free-fall                      no       no
> Data Set Management (DSM/TRIM) yes
> DSM - max 512byte blocks       yes              1
> DSM - deterministic read       yes              any value
> Host Protected Area (HPA)      yes      no      468883199/1
> HPA - Security                 no
> 
> A very similar device (firmware 2.15 instead of 2.25) in a 9.1 system
> returns no results to this command.  Not sure if that's 9.1/9.2
> difference of a firmware difference.

That will be 9.1 -> 9.2 differences.

So as suspected your drive is reporting it supports ATA_TRIM but
then refusing the command.

Now the question is why?

The most likely cause is a firmware bug.

I know its spec says its SAS but can you plug this drive into a
SATA controller such as on board Intel controller? If so does
work and then it correctly support delete's?

Note: The CAM SCSI layer currently prefers ATA_TRIM over UNMAP as in
all tests I've done it performs better.

    Regards
    Steve

================================================
This e.mail is private and confidential between Multiplay (UK) Ltd. and the person or entity to whom it is addressed. In the event of misdirection, the recipient is prohibited from using, copying, printing or otherwise disseminating it or any information contained in it. 

In the event of misdirection, illegible or incomplete transmission please telephone +44 845 868 1337
or return the E.mail to postmaster at multiplay.co.uk.