From: ching <lsching17@gmail.com>
To: linux-btrfs@vger.kernel.org
Subject: Re: enquiry about defrag
Date: Wed, 12 Sep 2012 07:33:02 +0800 [thread overview]
Message-ID: <504FCA2E.90906@gmail.com> (raw)
In-Reply-To: <20120911114559.GV17430@twin.jikos.cz>
On 09/11/2012 07:45 PM, David Sterba wrote:
> On Tue, Sep 11, 2012 at 07:12:58PM +0800, ching wrote:
>>> 1. According to btrfs wiki, defragment a COW file will produce two unrelated files.
>>>
>>> Does it apply to the "autodefrag" mount option?
>> can anybody helps on question 1?
> The data blocks associated with the files (that were originally created
> by snapshotting and thus shared the same blocks) will become unshared,
> so yes it would appear like two unlreated files.
>
> Autodefrag option affects only newly written data. With current
> implementation it could unshare some extents if the defragged range
> picked by autodefrag logic overlaps with an existing one.
>
> >From my experience, running 'btrfs fi defrag' with autodefrag on
> produced better result. Beware that there are some unfixed deadlocks
> that may happen with autodefrag enabled.
>
> david
>
thanks for your help very much :)
prev parent reply other threads:[~2012-09-11 23:33 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-09 0:03 enquiry about defrag ching
2012-09-09 0:30 ` Jan Steffens
2012-09-09 7:49 ` ching
2012-09-09 9:11 ` Fajar A. Nugraha
2012-09-09 12:05 ` ching
2012-09-10 12:19 ` ching
2012-09-10 13:10 ` Liu Bo
2012-09-10 23:21 ` ching
2012-09-11 1:28 ` Li Zefan
2012-09-11 11:12 ` ching
2012-09-10 9:23 ` Alex Lyakas
2012-09-11 11:12 ` ching
2012-09-11 11:45 ` David Sterba
2012-09-11 23:33 ` ching [this message]
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=504FCA2E.90906@gmail.com \
--to=lsching17@gmail.com \
--cc=linux-btrfs@vger.kernel.org \
/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.