From: Li Zefan <lizf@cn.fujitsu.com>
To: uzytkownik2@gmail.com
Cc: linux-btrfs@vger.kernel.org
Subject: Re: Inefficient storing of ISO images with compress=lzo
Date: Mon, 19 Sep 2011 11:13:19 +0800 [thread overview]
Message-ID: <4E76B34F.9030206@cn.fujitsu.com> (raw)
In-Reply-To: <4E76AEB9.4080109@cn.fujitsu.com>
Li Zefan wrote:
> Maciej Marcin Piechotka wrote:
>> I've noticed that:
>>
>> - with x86-64 Fedora 15 DVD install images:
>> - du -sh <ROOT VOLUME> was 36 GB
>> - btrfs df | grep -i data have shown over 40 GB used
>> - without
>> - du -sh <ROOT VOLUME> is 34 GB
>> - btrfs df | grep -i data have shown less then 34 GB used
>>
>> It seems that iso files are considered compressable while they may not be (and penalty is severe - 3x).
>>
>
> With compress option specified, btrfs will try to compress the file, at most
> 128K at one time, and if the compressed result is not smaller, the file will
> be marked as uncompressable.
>
> I just tried with Fedora-14-i386-DVD.iso, and the first 896K is compressed,
> with a compress ratio about 71.7%, and the remaining data is not compressed.
>
correct: the compression ratio is 38.3%, pretty good :)
next prev parent reply other threads:[~2011-09-19 3:13 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-18 23:32 Inefficient storing of ISO images with compress=lzo Maciej Marcin Piechotka
2011-09-19 2:53 ` Li Zefan
2011-09-19 3:13 ` Li Zefan [this message]
2011-09-19 23:06 ` Maciej Marcin Piechotka
2011-09-20 2:19 ` Li Zefan
2011-09-20 14:29 ` David Sterba
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=4E76B34F.9030206@cn.fujitsu.com \
--to=lizf@cn.fujitsu.com \
--cc=linux-btrfs@vger.kernel.org \
--cc=uzytkownik2@gmail.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.