From: Florian Weimer <fweimer@bfk.de>
To: Stewart Smith <stewart@flamingspork.com>
Cc: Christoph Hellwig <hch@infradead.org>, xfs@oss.sgi.com
Subject: Re: XFS on 2.6.26: reading the first 4K of a large file takes ages
Date: Fri, 21 May 2010 06:43:15 +0000 [thread overview]
Message-ID: <828w7d69h8.fsf@mid.bfk.de> (raw)
In-Reply-To: <87zkztojwh.fsf@willster.local.flamingspork.com> (Stewart Smith's message of "Fri\, 21 May 2010 16\:20\:46 +1000")
* Stewart Smith:
> On Thu, 20 May 2010 12:11:00 +0000, Florian Weimer <fweimer@bfk.de> wrote:
>> Thanks for confirming my hunch. I don't think it's worth fixing this
>> in XFS. The database should call posix_fallocate() before flushing
>> its internal cache to the file in essentially random order, but it's
>> difficult to get upstream to implement this (the source code is a bit
>> hard to follow, unfortunately).
>
> Which database?
Oracle Berkeley DB.
> You could always mount with allocsize
This happens with "allocsize=4194304".
> or use other tools to do the preallocation before things got too
> bad.
Is there a way to transparently preallocate a few GB after the current
end of the file? That would be helpful because Berkeley DB wouldn't
have to know about it.
It's a legacy system, otherwise I would invest more effort into
putting some sort of preallocation somewhere deep into Berkeley DB.
--
Florian Weimer <fweimer@bfk.de>
BFK edv-consulting GmbH http://www.bfk.de/
Kriegsstraße 100 tel: +49-721-96201-1
D-76133 Karlsruhe fax: +49-721-96201-99
_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs
next prev parent reply other threads:[~2010-05-21 6:41 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-19 11:33 XFS on 2.6.26: reading the first 4K of a large file takes ages Florian Weimer
2010-05-19 11:48 ` Christoph Hellwig
2010-05-19 23:27 ` Dave Chinner
2010-05-20 12:11 ` Florian Weimer
2010-05-21 6:20 ` Stewart Smith
2010-05-21 6:43 ` Florian Weimer [this message]
2010-05-21 8:26 ` Dave Chinner
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=828w7d69h8.fsf@mid.bfk.de \
--to=fweimer@bfk.de \
--cc=hch@infradead.org \
--cc=stewart@flamingspork.com \
--cc=xfs@oss.sgi.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.