From: Nathan Scott <nathans@aconex.com>
To: Michael Monnerie <michael.monnerie@is.it-management.at>
Cc: xfs@oss.sgi.com
Subject: Re: 4K drives, sectsz=512, bsize=4096
Date: Wed, 1 Sep 2010 08:34:28 +1000 (EST) [thread overview]
Message-ID: <1177874643.527261283294068615.JavaMail.root@mail-au.aconex.com> (raw)
In-Reply-To: <201009010007.23899@zmi.at>
----- "Michael Monnerie" <michael.monnerie@is.it-management.at> wrote:
> On Dienstag, 31. August 2010 Eric Sandeen wrote:
> > If you do it right (and especially vs. if you do it wrong) it
> > should be a bit faster if all IOs are 4k aligned on the disk.
>
> And that's what's interesting me: why? Won't XFS do all I/Os at
> minimum
> for a given block size? Or is it possible XFS does write only a single
> sector? I'd expect the smallest I/O size to be the block size, but it
> seems I'm wrong?
Log I/O and direct writes are sector sized & aligned.
> I guess there's no way to "convert" an existing XFS with
> sectsz=512,bsize=4096 to sectsz=4096,bsize=4096? Maybe that's only a
> flag that can be changed?
There's no way (other than dump, mkfs & restore), the filesystem is laid
out differently (most data structures, like superblocks and other metadata
become 4K aligned).
cheers.
--
Nathan
_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs
next prev parent reply other threads:[~2010-08-31 22:33 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-30 7:56 4K drives, sectsz=512, bsize=4096 Michael Monnerie
2010-08-31 21:01 ` Michael Monnerie
2010-08-31 21:16 ` Eric Sandeen
2010-08-31 22:07 ` Michael Monnerie
2010-08-31 22:15 ` Eric Sandeen
2010-08-31 23:12 ` Michael Monnerie
2010-08-31 22:34 ` Nathan Scott [this message]
2010-09-01 5:35 ` Gim Leong Chin
2010-09-01 5:59 ` Nathan Scott
2010-09-01 7:38 ` Michael Monnerie
2010-09-01 10:13 ` Christoph Hellwig
2010-09-01 10:24 ` Christoph Hellwig
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=1177874643.527261283294068615.JavaMail.root@mail-au.aconex.com \
--to=nathans@aconex.com \
--cc=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 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.