From: Goffredo Baroncelli <kreijack@inwind.it>
To: Lennart Poettering <lennart@poettering.net>
Cc: Duncan <1i5t5.duncan@cox.net>,
linux-btrfs@vger.kernel.org, systemd-devel@lists.freedesktop.org
Subject: Re: [systemd-devel] Slow startup of systemd-journal on BTRFS
Date: Mon, 16 Jun 2014 18:32:53 +0200 [thread overview]
Message-ID: <539F1C35.6060302@inwind.it> (raw)
In-Reply-To: <20140615221307.GE24386@tango.0pointer.de>
Hi Lennart,
On 06/16/2014 12:13 AM, Lennart Poettering wrote:
> I am not really following though why this trips up btrfs though. I am
> not sure I understand why this breaks btrfs COW behaviour. I mean,
> fallocate() isn't necessarily supposed to write anything really, it's
> mostly about allocating disk space in advance. I would claim that
> journald's usage of it is very much within the entire reason why it
> exists...
I performed several tests, trying different setups [1]. One of these was replacing the posix_fallocate() with a truncate, to check where is the problem. The conclusion was that *posix_fallocate() is NOT the problem*.
In another reply you stated that systemd-journald appends some data at the end of file, then update some data in the middle. I think this is the reason because the file becomes quickly fragmented.
[1] Let me to revise the english, the I will post the results.
--
gpg @keyserver.linux.it: Goffredo Baroncelli (kreijackATinwind.it>
Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5
next prev parent reply other threads:[~2014-06-16 16:29 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-12 11:13 R: Re: Slow startup of systemd-journal on BTRFS Goffredo Baroncelli <kreijack@libero.it>
2014-06-12 12:37 ` Duncan
2014-06-12 23:24 ` Dave Chinner
2014-06-13 22:19 ` Goffredo Baroncelli
2014-06-14 2:53 ` Duncan
2014-06-14 7:52 ` Goffredo Baroncelli
2014-06-15 5:43 ` Duncan
2014-06-15 22:39 ` [systemd-devel] " Lennart Poettering
2014-06-15 22:13 ` Lennart Poettering
2014-06-16 0:17 ` Russell Coker
2014-06-16 1:06 ` John Williams
2014-06-16 2:19 ` Russell Coker
2014-06-16 10:14 ` Lennart Poettering
2014-06-16 10:35 ` Russell Coker
2014-06-16 11:16 ` Austin S Hemmelgarn
2014-06-16 11:56 ` Andrey Borzenkov
2014-06-16 16:05 ` Josef Bacik
2014-06-16 19:52 ` Martin
2014-06-16 20:20 ` Josef Bacik
2014-06-17 0:15 ` Austin S Hemmelgarn
2014-06-17 1:13 ` cwillu
2014-06-17 12:24 ` Martin
2014-06-17 17:56 ` Chris Murphy
2014-06-17 18:46 ` Filipe Brandenburger
2014-06-17 19:42 ` Goffredo Baroncelli
2014-06-17 21:12 ` Lennart Poettering
2014-06-16 16:32 ` Goffredo Baroncelli [this message]
2014-06-16 18:47 ` Goffredo Baroncelli
2014-06-19 1:13 ` Dave Chinner
2014-06-14 10:59 ` Kai Krakow
2014-06-15 5:02 ` Duncan
2014-06-15 11:18 ` Kai Krakow
2014-06-15 21:45 ` Martin Steigerwald
2014-06-15 21:51 ` Hugo Mills
2014-06-15 22:43 ` [systemd-devel] " Lennart Poettering
2014-06-15 21:31 ` Martin Steigerwald
2014-06-15 21:37 ` Hugo Mills
2014-06-17 8:22 ` Duncan
-- strict thread matches above, loose matches on Subject: below --
2014-06-11 21:28 Goffredo Baroncelli
2014-06-12 1:21 ` Dave Chinner
2014-06-12 1:37 ` Dave Chinner
2014-06-12 2:32 ` Chris Murphy
2014-06-15 22:34 ` [systemd-devel] " Lennart Poettering
2014-06-16 4:01 ` Chris Murphy
2014-06-16 4:38 ` cwillu
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