Attempting ATA TRIM on SAS devices?

[Garrett Wollman]

<<On Wed, 8 Jan 2014 23:57:57 -0000, "Steven Hartland" <killing at multiplay.co.uk> said:

> You could just force the delete_method to UNMAP then:
> kern.cam.da.X.delete_method=UNMAP

I'm not sure that that works, given that the zpool is auto-imported at
boot time and I don't know which da units will be assigned to the SSDs
in question (no way to pin them so far as I can tell).  Does ZFS
generate BIO_DELETE on the cache devices at any time other than pool
import?

-GAWollman