Linux Btrfs filesystem development
 help / color / mirror / Atom feed
From: Chris Mason <chris.mason@oracle.com>
To: "Fajar A. Nugraha" <list@fajar.net>
Cc: Lubos Kolouch <lubos.kolouch@gmail.com>, linux-btrfs@vger.kernel.org
Subject: Re: How to remount btrfs without compression?
Date: Wed, 9 Nov 2011 08:01:34 -0500	[thread overview]
Message-ID: <20111109130134.GL4149@shiny> (raw)
In-Reply-To: <CAG1y0scE__f0BDyZz82z97jCX7DvzhDgXeh7Kh5pm31eXB=Wpg@mail.gmail.com>

On Wed, Nov 09, 2011 at 03:04:01PM +0700, Fajar A. Nugraha wrote:
> On Wed, Nov 9, 2011 at 2:48 PM, Lubos Kolouch <lubos.kolouch@gmail.com> wrote:
> > Sorry for possibly OT question - when I have historical btrfs system
> > mounted with zlib compression,
> >
> > can I remount it with lzo ?
> 
> yes
> 
> > What will happen? Will the COW be broken
> > and the files taking duplicate space? Or will the Universe explode and
> > be replaced with something even more bizzare?
> 
> New written block/extents will use lzo compression (if it's
> compressible, or if it's mounted with compress-force). Old, unmodified
> block/extents will remain unchanged, using zlib or uncompressed.

This is correct, your old stuff will be zlib and your new stuff lzo.
The compression type is recorded on a per-extent basis and the global
switch just decides what type of compression to use for new writes.

-chris


  reply	other threads:[~2011-11-09 13:01 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-07  0:53 How to remount btrfs without compression? dima
2011-11-07 12:19 ` Martin Steigerwald
2011-11-08  0:55   ` dima
2011-11-08  1:06     ` Eric Griffith
2011-11-08  1:52       ` Fajar A. Nugraha
2011-11-08  1:54         ` Eric Griffith
2011-11-08  2:00           ` dima
2011-11-08 15:01             ` Chris Mason
2011-11-08 15:12               ` Chris Mason
2011-11-09  1:01                 ` dima
2011-11-09  7:48                   ` Lubos Kolouch
2011-11-09  8:03                     ` Dmitry Olenin
2011-11-10  6:57                       ` Lubos Kolouch
2011-11-10  7:04                         ` Dmitry Olenin
2011-11-09  8:04                     ` Fajar A. Nugraha
2011-11-09 13:01                       ` Chris Mason [this message]
2011-11-10  0:11                   ` David Sterba
2011-11-10  2:23                     ` dima
2011-11-11 13:29                       ` dima

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=20111109130134.GL4149@shiny \
    --to=chris.mason@oracle.com \
    --cc=linux-btrfs@vger.kernel.org \
    --cc=list@fajar.net \
    --cc=lubos.kolouch@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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox