From: Phil Karn <karn@ka9q.net>
To: Paul Jones <paul@pauljones.id.au>
Cc: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>,
"linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>
Subject: Re: Extremely slow device removals
Date: Sat, 2 May 2020 00:20:42 -0700 [thread overview]
Message-ID: <CAMwB8mhGkcM3DCTusuHAi-cQcr-FrA5cq4hVYfv+65zn_QjAig@mail.gmail.com> (raw)
In-Reply-To: <SYBPR01MB389730010988EC44E7D109EE9EA80@SYBPR01MB3897.ausprd01.prod.outlook.com>
So I'm trying to figure out the advantage of including RAID 1 inside
btrfs instead of just running it over a conventional (fs-agnostic)
RAID subsystem.
I was originally really intrigued by the idea of integrating RAID into
the file system since it seemed like you could do more that way, or at
least do things more efficiently. For example, when adding or
replacing a mirror you'd only have to copy those parts of the disk
that actually contain data. That promised better performance. But if
those actually-used blocks are copied in small pieces and in random
order so the operation is far slower than the logical equivalent of
"dd if=disk1 of=disk2', then what's left?
Even the ability to use drives of different sizes isn't unique to
btrfs. You can use LVM to concatenate smaller volumes into larger
logical ones.
Phil
next prev parent reply other threads:[~2020-05-02 7:20 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-28 7:22 Extremely slow device removals Phil Karn
2020-04-30 17:31 ` Phil Karn
2020-04-30 18:13 ` Jean-Denis Girard
2020-05-01 8:05 ` Phil Karn
2020-05-02 3:35 ` Zygo Blaxell
[not found] ` <CAMwB8mjUw+KV8mxg8ynPsv0sj5vSpwG7_khw=oP5n+SnPYzumQ@mail.gmail.com>
2020-05-02 4:31 ` Zygo Blaxell
2020-05-02 4:48 ` Paul Jones
2020-05-02 5:25 ` Phil Karn
2020-05-02 6:04 ` Remi Gauvin
2020-05-02 7:20 ` Zygo Blaxell
2020-05-02 7:27 ` Phil Karn
2020-05-02 7:52 ` Zygo Blaxell
2020-05-02 6:00 ` Zygo Blaxell
2020-05-02 6:23 ` Paul Jones
2020-05-02 7:20 ` Phil Karn [this message]
2020-05-02 7:42 ` Zygo Blaxell
2020-05-02 8:22 ` Phil Karn
2020-05-02 8:24 ` Phil Karn
2020-05-02 9:09 ` Zygo Blaxell
2020-05-02 17:48 ` Chris Murphy
2020-05-03 5:26 ` Zygo Blaxell
2020-05-03 5:39 ` Chris Murphy
2020-05-03 6:05 ` Chris Murphy
2020-05-04 2:09 ` Phil Karn
2020-05-02 7:43 ` Jukka Larja
2020-05-02 4:49 ` Phil Karn
2020-04-30 18:40 ` Chris Murphy
2020-04-30 19:59 ` Phil Karn
2020-04-30 20:27 ` Alexandru Dordea
2020-04-30 20:58 ` Phil Karn
2020-05-01 2:47 ` Zygo Blaxell
2020-05-01 4:48 ` Phil Karn
2020-05-01 6:05 ` Alexandru Dordea
2020-05-01 7:29 ` Phil Karn
2020-05-02 4:18 ` Zygo Blaxell
2020-05-02 4:48 ` Phil Karn
2020-05-02 5:00 ` Phil Karn
2020-05-03 2:28 ` Phil Karn
2020-05-04 7:39 ` Phil Karn
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