From: Christoph Hellwig <hch@infradead.org>
To: Dave Chinner <david@fromorbit.com>
Cc: Nikolai Grigoriev <ngrigoriev@gmail.com>,
linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-raid@vger.kernel.org, linux-mm@kvack.org,
Jens Axboe <axboe@kernel.dk>
Subject: Re: ext4 vs btrfs performance on SSD array
Date: Mon, 1 Sep 2014 18:22:22 -0700 [thread overview]
Message-ID: <20140902012222.GA21405@infradead.org> (raw)
In-Reply-To: <20140902000822.GA20473@dastard>
On Tue, Sep 02, 2014 at 10:08:22AM +1000, Dave Chinner wrote:
> Pretty obvious difference: avgrq-sz. btrfs is doing 512k IOs, ext4
> and XFS are doing is doing 128k IOs because that's the default block
> device readahead size. 'blockdev --setra 1024 /dev/sdd' before
> mounting the filesystem will probably fix it.
Btw, it's really getting time to make Linux storage fs work out the
box. There's way to many things that are stupid by default and we
require everyone to fix up manually:
- the ridiculously low max_sectors default
- the very small max readahead size
- replacing cfq with deadline (or noop)
- the too small RAID5 stripe cache size
and probably a few I forgot about. It's time to make things perform
well out of the box..
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@infradead.org>
To: Dave Chinner <david@fromorbit.com>
Cc: Nikolai Grigoriev <ngrigoriev@gmail.com>,
linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-raid@vger.kernel.org, linux-mm@kvack.org,
Jens Axboe <axboe@kernel.dk>
Subject: Re: ext4 vs btrfs performance on SSD array
Date: Mon, 1 Sep 2014 18:22:22 -0700 [thread overview]
Message-ID: <20140902012222.GA21405@infradead.org> (raw)
In-Reply-To: <20140902000822.GA20473@dastard>
On Tue, Sep 02, 2014 at 10:08:22AM +1000, Dave Chinner wrote:
> Pretty obvious difference: avgrq-sz. btrfs is doing 512k IOs, ext4
> and XFS are doing is doing 128k IOs because that's the default block
> device readahead size. 'blockdev --setra 1024 /dev/sdd' before
> mounting the filesystem will probably fix it.
Btw, it's really getting time to make Linux storage fs work out the
box. There's way to many things that are stupid by default and we
require everyone to fix up manually:
- the ridiculously low max_sectors default
- the very small max readahead size
- replacing cfq with deadline (or noop)
- the too small RAID5 stripe cache size
and probably a few I forgot about. It's time to make things perform
well out of the box..
--
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next prev parent reply other threads:[~2014-09-02 1:22 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-26 23:39 ext4 vs btrfs performance on SSD array Nikolai Grigoriev
2014-08-27 7:10 ` Duncan
2014-08-27 21:59 ` Nikolai Grigoriev
2014-09-02 0:08 ` Dave Chinner
2014-09-02 1:22 ` Christoph Hellwig [this message]
2014-09-02 1:22 ` Christoph Hellwig
2014-09-02 10:39 ` Zack Coffey
2014-09-02 11:31 ` Theodore Ts'o
2014-09-02 11:31 ` Theodore Ts'o
2014-09-02 14:20 ` Jan Kara
2014-09-02 14:20 ` Jan Kara
2014-09-02 14:55 ` Theodore Ts'o
2014-09-02 14:55 ` Theodore Ts'o
2014-09-02 12:55 ` Zack Coffey
2014-09-02 12:55 ` Zack Coffey
2014-09-02 13:40 ` Austin S Hemmelgarn
2014-09-03 0:01 ` NeilBrown
2014-09-05 16:08 ` Christoph Hellwig
2014-09-05 16:08 ` Christoph Hellwig
2014-09-05 16:40 ` Jeff Moyer
2014-09-05 16:40 ` Jeff Moyer
2014-09-05 16:50 ` Jens Axboe
2014-09-05 16:50 ` Jens Axboe
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