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Date:   Sat, 4 Jul 2020 13:49:17 +0200
From:   Pavel Machek <pavel@ucw.cz>
To:     David Laight <David.Laight@ACULAB.COM>
Cc:     Ming Lei <tom.leiming@gmail.com>,
        Henrique de Moraes Holschuh <hmh@hmh.eng.br>,
        Damien Le Moal <Damien.LeMoal@wdc.com>,
        Simon Arlott <simon@octiron.net>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
        "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>
Subject: Re: [PATCH] scsi: sd: stop SSD (non-rotational) disks before reboot
Message-ID: <20200704114917.GB16083@amd>
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Hi!

> > Sent: 02 July 2020 22:17
> > > > during a FLASH write or erase can cause from weakened cells, to much
> > > > larger damage.  It is possible to harden the chip or the design aga=
inst
> > > > this, but it is *expensive*.  And even if warded off by hardening a=
nd no
> > > > FLASH damage happens, an erase/program cycle must be done on the wh=
ole
> > > > erase block to clean up the incomplete program cycle.
> > >
> > > It should have been SSD's(including FW) responsibility to avoid data =
loss when
> > > the SSD is doing its own BG writing, because power cut can happen any=
 time
> > > from SSD's viewpoint.
> >=20
> > It should be their responsibility. But we know how well that works
> > (not well), so we try hard (and should try hard) to power SSDs down
> > cleanly.
>=20
> I hope modern SSD disks are better than very old CF drives.

Testing showed there were not few yars ago.

> I had one where the entire contents got scrambled after an unexpected
> power removal.

If you have SSD you are willing to kill, I believe you can get to same
result with a bit of patience.

Best regards,
								Pavel--=20
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo=
g.html

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