From: Greg Banks <gnb@sgi.com>
To: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: David Rees <drees76@gmail.com>, linux-nfs@vger.kernel.org
Subject: Re: Horrible NFS Client Performance During Heavy Server IO
Date: Tue, 17 Mar 2009 15:43:59 +1100 [thread overview]
Message-ID: <49BF2A8F.7030607@sgi.com> (raw)
In-Reply-To: <1236978608.7265.41.camel-rJ7iovZKK19ZJLDQqaL3InhyD016LWXt@public.gmane.org>
Trond Myklebust wrote:
> On Fri, 2009-03-13 at 13:36 -0700, David Rees wrote:
>
>>
>
> You don't need conv=fdatasync when writing to NFS. The close-to-open
> cache consistency automatically guarantees fdatasync on close().
>
Yes...but at least some versions of dd will print a performance number
at the end, where the time delta used in the calculation includes the
fdatasync() time but not the close() time. So conv=fdatasync is a
useful trick to get accurate performance numbers from dd. Personally I
don't use that metric from dd because it's a simple overall average and
I like to watch the time behaviour of the transfer rate.
--
Greg Banks, P.Engineer, SGI Australian Software Group.
the brightly coloured sporks of revolution.
I don't speak for SGI.
prev parent reply other threads:[~2009-03-17 4:39 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-13 20:36 Horrible NFS Client Performance During Heavy Server IO David Rees
2009-03-13 21:10 ` Trond Myklebust
2009-03-13 21:32 ` David Rees
2009-03-13 21:40 ` Trond Myklebust
2009-03-13 21:59 ` David Rees
2009-03-13 22:29 ` Trond Myklebust
2009-03-13 23:05 ` David Rees
2009-03-17 4:54 ` Greg Banks
2009-03-17 6:28 ` David Rees
[not found] ` <1236978608.7265.41.camel-rJ7iovZKK19ZJLDQqaL3InhyD016LWXt@public.gmane.org>
2009-03-17 4:43 ` Greg Banks [this message]
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=49BF2A8F.7030607@sgi.com \
--to=gnb@sgi.com \
--cc=drees76@gmail.com \
--cc=linux-nfs@vger.kernel.org \
--cc=trond.myklebust@fys.uio.no \
/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.