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Sender: Tejun Heo <htejun@gmail.com>
Date: Mon, 8 May 2017 13:43:03 -0400
From: Tejun Heo <tj@kernel.org>
To: Pavel Machek <pavel@ucw.cz>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>,
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 Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Subject: Re: Race to power off harming SATA SSDs
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Hello,

On Mon, May 08, 2017 at 06:43:22PM +0200, Pavel Machek wrote:
> What I was trying to point out was that storage people try to treat
> SSDs as HDDs... and SSDs are very different. Harddrives mostly survive
> powerfails (with emergency parking), while it is very, very difficult
> to make SSD survive random powerfail, and we have to make sure we
> always powerdown SSDs "cleanly".

We do.

The issue raised is that some SSDs still increment the unexpected
power loss count even after clean shutdown sequence and that the
kernel should wait for some secs before powering off.

We can do that for select devices but I want something more than "this
SMART counter is getting incremented" before doing that.

Thanks.

-- 
tejun