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From: Ulli Horlacher <framstag@rus.uni-stuttgart.de>
To: linux-btrfs@vger.kernel.org
Subject: defragmenting best practice?
Date: Tue, 12 Sep 2017 18:28:43 +0200	[thread overview]
Message-ID: <20170912162843.GA32233@rus.uni-stuttgart.de> (raw)
In-Reply-To: <20170831070558.GB5783@rus.uni-stuttgart.de>

On Thu 2017-08-31 (09:05), Ulli Horlacher wrote:
> When I do a 
> btrfs filesystem defragment -r /directory
> does it defragment really all files in this directory tree, even if it
> contains subvolumes?
> The man page does not mention subvolumes on this topic.

No answer so far :-(

But I found another problem in the man-page:

  Defragmenting with Linux kernel versions < 3.9 or >= 3.14-rc2 as well as
  with Linux stable kernel versions >= 3.10.31, >= 3.12.12 or >= 3.13.4
  will break up the ref-links of COW data (for example files copied with
  cp --reflink, snapshots or de-duplicated data). This may cause
  considerable increase of space usage depending on the broken up
  ref-links.

I am running Ubuntu 16.04 with Linux kernel 4.10 and I have several
snapshots.
Therefore, I better should avoid calling "btrfs filesystem defragment -r"?

What is the defragmenting best practice?
Avoid it completly?



-- 
Ullrich Horlacher              Server und Virtualisierung
Rechenzentrum TIK         
Universitaet Stuttgart         E-Mail: horlacher@tik.uni-stuttgart.de
Allmandring 30a                Tel:    ++49-711-68565868
70569 Stuttgart (Germany)      WWW:    http://www.tik.uni-stuttgart.de/
REF:<20170831070558.GB5783@rus.uni-stuttgart.de>

  reply	other threads:[~2017-09-12 16:28 UTC|newest]

Thread overview: 56+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-31  7:05 btrfs filesystem defragment -r -- does it affect subvolumes? Ulli Horlacher
2017-09-12 16:28 ` Ulli Horlacher [this message]
2017-09-12 17:27   ` defragmenting best practice? Austin S. Hemmelgarn
2017-09-14  7:54     ` Duncan
2017-09-14 12:28       ` Austin S. Hemmelgarn
2017-09-14 11:38   ` Kai Krakow
2017-09-14 13:31     ` Tomasz Kłoczko
2017-09-14 15:24       ` Kai Krakow
2017-09-14 15:47         ` Kai Krakow
2017-09-14 17:48         ` Tomasz Kłoczko
2017-09-14 18:53           ` Austin S. Hemmelgarn
2017-09-15  2:26             ` Tomasz Kłoczko
2017-09-15 12:23               ` Austin S. Hemmelgarn
2017-09-14 20:17           ` Kai Krakow
2017-09-15 10:54           ` Michał Sokołowski
2017-09-15 11:13             ` Peter Grandi
2017-09-15 13:07             ` Tomasz Kłoczko
2017-09-15 14:11               ` Michał Sokołowski
2017-09-15 16:35                 ` Peter Grandi
2017-09-15 17:08                 ` Kai Krakow
2017-09-15 19:10                   ` Tomasz Kłoczko
2017-09-20  6:38                     ` Dave
2017-09-20 11:46                       ` Austin S. Hemmelgarn
2017-09-21 20:10                         ` Kai Krakow
2017-09-21 23:30                           ` Dave
2017-09-21 23:58                           ` Kai Krakow
2017-09-22 11:22                           ` Austin S. Hemmelgarn
2017-09-22 20:29                             ` Marc Joliet
2017-09-21 11:09                       ` Duncan
2017-10-31 21:47                         ` Dave
2017-10-31 23:06                           ` Peter Grandi
2017-11-01  0:37                             ` Dave
2017-11-01 12:21                               ` Austin S. Hemmelgarn
2017-11-02  1:39                                 ` Dave
2017-11-02 11:07                                   ` Austin S. Hemmelgarn
2017-11-03  2:59                                     ` Dave
2017-11-03  7:12                                       ` Kai Krakow
2017-11-03  5:58                                   ` Marat Khalili
2017-11-03  7:19                                     ` Kai Krakow
2017-11-01 17:48                               ` Peter Grandi
2017-11-02  0:09                                 ` Dave
2017-11-02 11:17                                   ` Austin S. Hemmelgarn
2017-11-02 18:09                                     ` Dave
2017-11-02 18:37                                       ` Austin S. Hemmelgarn
2017-11-02  0:43                                 ` Peter Grandi
2017-11-02 21:16                               ` Kai Krakow
2017-11-03  2:47                                 ` Dave
2017-11-03  7:26                                   ` Kai Krakow
2017-11-03 11:30                                     ` Austin S. Hemmelgarn
     [not found]                             ` <CAH=dxU47-52-asM5vJ_-qOpEpjZczHw7vQzgi1-TeKm58++zBQ@mail.gmail.com>
2017-12-11  5:18                               ` Dave
2017-12-11  6:10                                 ` Timofey Titovets
2017-11-01  7:43                           ` Sean Greenslade
2017-11-01 13:31                           ` Duncan
2017-11-01 23:36                             ` Dave
2017-09-21 19:28                       ` Sean Greenslade
2017-09-20  7:34                     ` Dmitry Kudriavtsev

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