From: "Alexandre Depoutovitch" <adepoutovitch@vmware.com>
To: <linux-nfs@vger.kernel.org>
Subject: About Direct I/O
Date: Fri, 16 Mar 2012 11:14:04 -0700 (PDT) [thread overview]
Message-ID: <6866525b.00001bd8.0000023d@aldep-VC.vmware.com> (raw)
In-Reply-To: <CAAJC9VbxAcE+DqjqaZ-9K4HKpAWKgg0_B9_QFk64b5V-QdotQA@mail.gmail.com>
Hello,
I am trying to do random sector aligned writes to an NFS mounted disk. The
performance is order of magnitude worse than 4K (file system block size)
aligned I/O.
The reason is that NFS demon (Linux kernel 2.6.32) on the server side
always does buffered I/O, which behaves poorly for block unaligned
requests.
Is there a way to tell NFS daemon to use direct I/O?
If not, is it an implementation limitation or there is a fundamental
problem with using direct I/O in NFS server?
Thank you,
Alex
next prev parent reply other threads:[~2012-03-16 18:14 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-15 20:23 About pNFS installation process Bruno Silva
2012-03-16 0:16 ` Jim Rees
2012-03-16 18:14 ` Alexandre Depoutovitch [this message]
2012-03-16 20:35 ` About Direct I/O J. Bruce Fields
2012-03-16 20:58 ` Myklebust, Trond
2012-03-18 10:51 ` About pNFS installation process Lev Solomonov
2012-03-23 17:21 ` Bruno Silva
2012-03-23 18:02 ` Jim Rees
2012-04-04 0:20 ` Lev Solomonov
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