From: Phillip Susi <phill@thesusis.net>
To: Qu Wenruo <quwenruo.btrfs@gmx.com>
Cc: Jan Ziak <0xe2.0x9a.0x9b@gmail.com>, linux-btrfs@vger.kernel.org
Subject: Re: Btrfs autodefrag wrote 5TB in one day to a 0.5TB SSD without a measurable benefit
Date: Mon, 14 Mar 2022 16:09:08 -0400 [thread overview]
Message-ID: <87a6dscn20.fsf@vps.thesusis.net> (raw)
In-Reply-To: <078f9f05-3f8f-eef1-8b0b-7d2a26bf1f97@gmx.com>
Qu Wenruo <quwenruo.btrfs@gmx.com> writes:
> That's more or less expected.
>
> Autodefrag has two limitations:
>
> 1. Only defrag newer writes
> It doesn't defrag older fragments.
> This is the existing behavior from the beginning of autodefrag.
> Thus it's not that effective against small random writes.
I don't understand this bit. The whole point of defrag is to reduce the
fragmentation of previous writes. New writes should always attempt to
follow the previous one if possible. If auto defrag only changes the
behavior of new writes, then how does it change it and why is that not
the way new writes are always done?
next prev parent reply other threads:[~2022-03-14 20:10 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-06 15:59 Btrfs autodefrag wrote 5TB in one day to a 0.5TB SSD without a measurable benefit Jan Ziak
2022-03-07 0:48 ` Qu Wenruo
2022-03-07 2:23 ` Jan Ziak
2022-03-07 2:39 ` Qu Wenruo
2022-03-07 7:31 ` Qu Wenruo
2022-03-10 1:10 ` Jan Ziak
2022-03-10 1:26 ` Qu Wenruo
2022-03-10 4:33 ` Jan Ziak
2022-03-10 6:42 ` Qu Wenruo
2022-03-10 21:31 ` Jan Ziak
2022-03-10 23:27 ` Qu Wenruo
2022-03-11 2:42 ` Jan Ziak
2022-03-11 2:59 ` Qu Wenruo
2022-03-11 5:04 ` Jan Ziak
2022-03-11 16:31 ` Jan Ziak
2022-03-11 20:02 ` Jan Ziak
2022-03-11 23:04 ` Qu Wenruo
2022-03-11 23:28 ` Jan Ziak
2022-03-11 23:39 ` Qu Wenruo
2022-03-12 0:01 ` Jan Ziak
2022-03-12 0:15 ` Qu Wenruo
2022-03-12 3:16 ` Zygo Blaxell
2022-03-12 2:43 ` Zygo Blaxell
2022-03-12 3:24 ` Qu Wenruo
2022-03-12 3:48 ` Zygo Blaxell
2022-03-14 20:09 ` Phillip Susi [this message]
2022-03-14 22:59 ` Zygo Blaxell
2022-03-15 18:28 ` Phillip Susi
2022-03-15 19:28 ` Jan Ziak
2022-03-15 21:06 ` Zygo Blaxell
2022-03-15 22:20 ` Jan Ziak
2022-03-16 17:02 ` Zygo Blaxell
2022-03-16 17:48 ` Jan Ziak
2022-03-17 2:11 ` Zygo Blaxell
2022-03-16 18:46 ` Phillip Susi
2022-03-16 19:59 ` Zygo Blaxell
2022-03-20 17:50 ` Forza
2022-03-20 21:15 ` Zygo Blaxell
2022-03-08 21:57 ` Jan Ziak
2022-03-08 23:40 ` Qu Wenruo
2022-03-09 22:22 ` Jan Ziak
2022-03-09 22:44 ` Qu Wenruo
2022-03-09 22:55 ` Jan Ziak
2022-03-09 23:00 ` Jan Ziak
2022-03-09 4:48 ` Zygo Blaxell
2022-03-07 14:30 ` Phillip Susi
2022-03-08 21:43 ` Jan Ziak
2022-03-09 18:46 ` Phillip Susi
2022-03-09 21:35 ` Jan Ziak
2022-03-14 20:02 ` Phillip Susi
2022-03-14 21:53 ` Jan Ziak
2022-03-14 22:24 ` Remi Gauvin
2022-03-14 22:51 ` Zygo Blaxell
2022-03-14 23:07 ` Remi Gauvin
2022-03-14 23:39 ` Zygo Blaxell
2022-03-15 14:14 ` Remi Gauvin
2022-03-15 18:51 ` Zygo Blaxell
2022-03-15 19:22 ` Remi Gauvin
2022-03-15 21:08 ` Zygo Blaxell
2022-03-15 18:15 ` Phillip Susi
2022-03-16 16:52 ` Andrei Borzenkov
2022-03-16 18:28 ` Jan Ziak
2022-03-16 18:31 ` Phillip Susi
2022-03-16 18:43 ` Andrei Borzenkov
2022-03-16 18:46 ` Jan Ziak
2022-03-16 19:04 ` Zygo Blaxell
2022-03-17 20:34 ` Phillip Susi
2022-03-17 22:06 ` Zygo Blaxell
2022-03-16 12:47 ` Kai Krakow
2022-03-16 18:18 ` Jan Ziak
-- strict thread matches above, loose matches on Subject: below --
2022-06-17 0:20 Jan Ziak
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