From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Grzegorz Kulewski <kangur@polcom.net>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: How to flush data to disk reliably?
Date: Mon, 02 May 2005 18:52:38 +0100 [thread overview]
Message-ID: <1115056355.10370.37.camel@localhost.localdomain> (raw)
In-Reply-To: <Pine.LNX.4.62.0505021503470.11701@alpha.polcom.net>
> I am asking how to flush the data from these logs to disk. I know of
> several methods:
> 1. open with O_SYNC,
> 2. sync(2),
> 3. fsync,
> 4. fdatasync,
> 5. msync (if they are mmaped).
>
> Which of these are best and most reliable for (a/b) and for (IDE/SCSI)?
For scsi the combination of O_SYNC and ext3 or fsync and ext3 should be
reliable. fdatasync doesn't write back all the metadata so depending on
the use may not be sufficient. FAT based fs's I believe you need a
current kernel for full O_SYNC behaviour.
> What are differences between them?
See the manual pages and/or standard.
> other precautions that I should be aware of? What about write caches? Are
> write barriers implemented (on IDE and SATA/SCSI) or should I turn caches
> off?
SCSI shoule be fine, IDE turn off the write cache.
next prev parent reply other threads:[~2005-05-02 17:57 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-05-02 13:23 How to flush data to disk reliably? Grzegorz Kulewski
2005-05-02 17:52 ` Alan Cox [this message]
2005-05-02 19:18 ` Grzegorz Kulewski
2005-05-02 21:41 ` Alan Cox
2005-05-02 22:30 ` Bill Davidsen
2005-05-02 23:17 ` Arjan van de Ven
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=1115056355.10370.37.camel@localhost.localdomain \
--to=alan@lxorguk.ukuu.org.uk \
--cc=kangur@polcom.net \
--cc=linux-kernel@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.