public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: "Theodore Ts'o" <tytso@mit.edu>
To: Sam Vilain <sam@vilain.net>
Cc: Xin Zhao <uszhaoxin@gmail.com>,
	Arjan van de Ven <arjan@infradead.org>,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: question about possibility of data loss in Ext2/3 file system
Date: Fri, 24 Feb 2006 11:29:57 -0500	[thread overview]
Message-ID: <20060224162957.GA22097@thunk.org> (raw)
In-Reply-To: <43FE1110.1030707@vilain.net>

On Fri, Feb 24, 2006 at 08:46:24AM +1300, Sam Vilain wrote:
> Theodore Ts'o wrote:
> >>Also, the scheme you mentioned is just for new file creation. What
> >>will happen if I want to update an existing file? Say, I open file A,
> >>seek to offset 5000, write 4096 bytes, and then close. Do you know how
> >>ext2/3 handle this situation?
> >If you have a power failure right after the close, the data could be
> >lost.  This is true for pretty much all Unix filesystems, for
> >performance reasons.  If you care about the data hitting disk, the
> >application must use fsync().  
> 
> I always liked Sun's approach to this in Online Disk Suite - journal at 
> the block device level rather than the FS / application level. 
> Something I haven't seen from the Linux md-utils or DM.

You can do data block journalling in ext3.  But the performance impact
can be significant for some work loads.   TNSFAAFL.

						- Ted

  reply	other threads:[~2006-02-24 16:30 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-02-22 21:56 question about possibility of data loss in Ext2/3 file system Xin Zhao
2006-02-22 22:00 ` Arjan van de Ven
2006-02-22 22:34   ` Xin Zhao
2006-02-22 23:07     ` Andreas Dilger
2006-02-23  4:58     ` Theodore Ts'o
2006-02-23 19:46       ` Sam Vilain
2006-02-24 16:29         ` Theodore Ts'o [this message]
2006-02-26 21:27           ` Sam Vilain
2006-02-27  7:38             ` Xin Zhao
2006-02-28 16:56               ` Phillip Susi
2006-02-23 12:52     ` linux-os (Dick Johnson)

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=20060224162957.GA22097@thunk.org \
    --to=tytso@mit.edu \
    --cc=arjan@infradead.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=sam@vilain.net \
    --cc=uszhaoxin@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