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Date: Sun, 9 Dec 2012 16:41:25 +0600
From: Roman Mamedov <rm@romanrm.ru>
To: Jan Engelhardt <jengelh@inai.de>
Cc: Martin Steigerwald <Martin@lichtvoll.de>, linux-btrfs@vger.kernel.org,
        =?UTF-8?B?U3fDom1p?= Petaramesh <swami@petaramesh.org>
Subject: Re: BTRFS, getting darn slower everyday
Message-ID: <20121209164125.1bd91f23@natsu>
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On Sun, 9 Dec 2012 06:17:39 +0100 (CET)
Jan Engelhardt <jengelh@inai.de> wrote:

>=20
> On Sunday 2012-10-07 16:48, Martin Steigerwald wrote:
> >>=20
> >> # btrfs su li /
> >> ID 256 top level 5 path UBUNTU
> >> ID 259 top level 5 path UBUNTU/@
> >> ID 261 top level 5 path UBUNTU/@tmp
> >> ID 262 top level 5 path UBUNTU/@home
> >>[...]
> >
> >This could be 100 or more subvolumes / snapshots.
> >Maybe slowness could be related to this one.
>=20
> Absolutely. COW snapshots cause severe fragmentation (it's
> in their nature).

CoW filesystem incurs fragmentation by its nature, not specifically snapsho=
ts.
Even without snapshots, rewriting portions of existing files will write the
new blocks not over the original ones, but elsewhere, thus increasing
fragmentation.

--=20
With respect,
Roman

~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Stallman had a printer,
with code he could not see.
So he began to tinker,
and set the software free."

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