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Date: Wed, 22 Aug 2018 20:38:27 -0700
From: bob prohaska <fbsd@www.zefox.net>
To: Mark Millard <marklmi@yahoo.com>
Cc: FreeBSD Current <freebsd-current@freebsd.org>,
 bob prohaska <fbsd@www.zefox.net>
Subject: Re: CFT: TRIM Consolodation on UFS/FFS filesystems
Message-ID: <20180823033827.GA89801@www.zefox.net>
References: <170C703D-AA75-4EC9-93BA-D2CF3A7D6D5E@yahoo.com>
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On Tue, Aug 21, 2018 at 06:47:19PM -0700, Mark Millard wrote:
> 
> I've used a SSD both directly via SATA and via a USB enclosure,
> the same partitions/file systems across the uses. Only when it
> was SATA-style-use did TRIM work.
> 
This is likely the key to my question. If USB blocks the TRIM service 
the behavior of the device doesn't matter. 

As an aside, Sandisk now says:
"Please be informed that we have not tested running TRIM commands on USB flash drive 
and microSD cards therefore we would not be able to comment on it explicitly."

Thanks for reading,

bob prohaska