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From: Christoph Hellwig <hch@infradead.org>
To: Theodore Ts'o <tytso@mit.edu>
Cc: Sahitya Tummala <stummala@codeaurora.org>,
	Andreas Dilger <adilger.kernel@dilger.ca>,
	linux-ext4@vger.kernel.org
Subject: Re: fsync_mode mount option for ext4
Date: Tue, 28 May 2019 23:56:47 -0700	[thread overview]
Message-ID: <20190529065647.GA8405@infradead.org> (raw)
In-Reply-To: <20190529052332.GB6210@mit.edu>

On Wed, May 29, 2019 at 01:23:32AM -0400, Theodore Ts'o wrote:
> If you have protection against sudden shutdown, then nobarrier is
> perfectly safe --- which is to say, if it is guaranteed that any
> writes sent to device will be persisted after a crash, then nobarrier
> is perfectly safe.  So for example, if you are using ext4 connected to
> a million dollar EMC Storage Array, which has battery backup, using
> nobarrier is perfectly safe.

And while we had a few oddities in the past in general any such device
will obviously not claim to even have a volatile write cache, so
nobarrier or this broken proposed mount option won't actually make any
difference.

  reply	other threads:[~2019-05-29  6:56 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-28  3:22 fsync_mode mount option for ext4 Sahitya Tummala
2019-05-28  3:40 ` Theodore Ts'o
2019-05-28  3:48   ` Sahitya Tummala
2019-05-28 13:13     ` Theodore Ts'o
2019-05-29  4:07       ` Sahitya Tummala
2019-05-29  5:23         ` Theodore Ts'o
2019-05-29  6:56           ` Christoph Hellwig [this message]
2019-05-29 10:48           ` Sahitya Tummala
2019-05-29 15:13             ` Theodore Ts'o

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