I'm wondering how Hard Disk Sentinel checks the "TRIM feature status".
If I'm correct, it checks two things:
- Whether OS recognizes SSD correctly (and, thus, sends TRIM commands)
- Whether SSD itself declares the support of TRIM and DRAT (via "word169->bit0", "word69->bit14" and "word69->bit5")
( https://koitsu.files.wordpress.com/2013/02/trim_behaviour.png )
So, given two TRUE logical values here, hdsentinel would report, that TRIM is functioning OK, right?
So, it's a "theoretical conclusion", not an "experimental", is it?
Thus, hdsentinel would report "false positive" if there's something wrong with how controller (e.g. RAID) passes TRIM commands, for example, in the case, described here : http://www.win-raid.com/t1366f25-Nightmare-to-find-a-SSD-with-functional-TRIM-on-LSI-SAS.html .
I received some help on the linux-scsi list where it was suggested that for trim to work with LSI controllers, deterministic read after trim (read zero) is needed
I've noticed these two topics :