From: Michael Monnerie <michael.monnerie@is.it-management.at>
To: xfs@oss.sgi.com
Subject: Wiki entry for disk write caches and RAID controllers
Date: Thu, 5 Feb 2009 10:19:24 +0100 [thread overview]
Message-ID: <200902051019.24403@zmi.at> (raw)
I updated the sections about "disk write cache" and "RAID controllers",
please review and comment.
http://xfs.org/index.php/XFS_FAQ
I merged my original paragraph about "disk write cache" with the "What
is the problem with the write cache on journaled filesystems?" text.
On Donnerstag 05 Februar 2009 Dave Chinner wrote:
> What I missed was the "barriers turned on" - I was referring
> (context not quoted) to the fact that RAID5 is not unіque in it's
> ability to trash the filesystem on powerfail. You are right,
> barriers on a single disk should prevent filesystem corruption
> and will prevent loss of synchronously written data. only
> asynchronously written data will get lost (just like all the
> stuff sitting in RAM).
So can we say that 1 disk can let write cache on with barriers enabled?
For the Xyratex case: If all write caches are off (or write through),
does it matter if you use [no]barrier? I guess no, just want to be sure.
mfg zmi
--
// Michael Monnerie, Ing.BSc ----- http://it-management.at
// Tel: 0660 / 415 65 31 .network.your.ideas.
// PGP Key: "curl -s http://zmi.at/zmi.asc | gpg --import"
// Fingerprint: AC19 F9D5 36ED CD8A EF38 500E CE14 91F7 1C12 09B4
// Keyserver: wwwkeys.eu.pgp.net Key-ID: 1C1209B4
_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs
reply other threads:[~2009-02-05 9:20 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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=200902051019.24403@zmi.at \
--to=michael.monnerie@is.it-management.at \
--cc=xfs@oss.sgi.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