Switching from MFI to MRSAS

[Steven Hartland]

On 23/09/2015 22:32, Ryan Stone wrote:
> On Wed, Sep 23, 2015 at 12:59 PM, Tim Gustafson <tjg at ucsc.edu> wrote:
>
>> The mrsas driver man page says that it reports the disks as "da0",
>> "da1" and so on, and the man pages about TRIM support all say that it
>> works with "ada" and "da" drives.  So, I was hoping that the change in
>> driver technology would enable the TRIM command to work.
>>
>> I suppose I could update device.hints and loader.conf as describe,
>> reboot, and if the system doesn't come back up, just boot off a thumb
>> drive and re-edit those files back to their defaults...
>>
> The mrsas driver is interesting.  Your RAID volumes show up as da0, da1,
> etc, but they really shouldn't.  I'm doubtful that TRIM will work here
> because the drives are not truly directly attached, even though the mrsas
> driver is misleading the kernel into thinking that they are.
>
> You can always give a try, though.
camcontrol identify da0 will give you an indication

ZFS will tell you straight away after a file delete:
sysctl kstat.zfs.misc.zio_trim

     Regards
     Steve