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Date: Mon, 3 Apr 2017 13:41:39 +0500
From: Roman Mamedov <rm@romanrm.net>
To: Andrei Borzenkov <arvidjaar@gmail.com>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: Is btrfs-convert able to deal with sparse files in a ext4
 filesystem?
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On Sun, 2 Apr 2017 09:30:46 +0300
Andrei Borzenkov <arvidjaar@gmail.com> wrote:

> 02.04.2017 03:59, Duncan пишет:
> > 
> > 4) In fact, since an in-place convert is almost certainly going to take 
> > more time than a blow-away and restore from backup,
> 
> This caught my eyes. Why? In-place convert just needs to recreate
> metadata. If you have multi-terabyte worth of data copying them twice
> hardly can be faster.

In-place convert is most certainly faster than copy-away and restore, in fact
it can be very fast if you use the option to not calculate checksums for the
entire filesystem's data (btrfs-convert -d).

-- 
With respect,
Roman