From: Mikhail Morfikov <mmorfikov@gmail.com>
To: Theodore Ts'o <tytso@mit.edu>
Cc: linux-ext4@vger.kernel.org
Subject: Re: Question about ext4 extents and file fragmentation
Date: Thu, 21 Mar 2019 16:59:34 +0100 [thread overview]
Message-ID: <d32355a6-19b3-7861-9323-a761ea02d9f5@gmail.com> (raw)
In-Reply-To: <20190321150520.GE9434@mit.edu>
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On 21/03/2019 16:05, Theodore Ts'o wrote:
> It *could* be read sequentially from the beginning of the file to the
> end. There are many things that might cause that not to happen, that
> have nothing to do with how we store the logical to physicla map.
And this is what I wanted to know, because some people tell that if you
store a file in a filesystem, it can't be read sequentially as a whole
because of the filesystem layer (compared to "dd if=/dev/sda ..."). So
the filesystem layer doesn't really matter and doesn't really add any
additional delays compared to the raw read of a device when we deal with
data that is stored in contiguous blocks. I know that many things can
prevent the sequential read from happening, but I just wanted it to be
clarified.
Thank you for the answer, I really appreciate it.
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prev parent reply other threads:[~2019-03-21 15:59 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-20 22:44 Question about ext4 extents and file fragmentation Mikhail Morfikov
2019-03-21 3:18 ` Theodore Ts'o
2019-03-21 9:29 ` Mikhail Morfikov
2019-03-21 15:05 ` Theodore Ts'o
2019-03-21 15:59 ` Mikhail Morfikov [this message]
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