On Sep 22, 2006, at 15:00 , [EMAIL PROTECTED] wrote:

On Fri, Sep 22, 2006 at 01:52:02PM -0400, Jim Nasby wrote:
I thought folks might be interested in this... note in particular the
comment about linux.
From: Greg 'groggy' Lehey <[EMAIL PROTECTED]>
Date: June 26, 2006 11:34:12 PM EDT
To: leo huang <[EMAIL PROTECTED]>
Cc: freebsd-performance@freebsd.org
Subject: Re: Is the fsync() fake on FreeBSD6.1?
My understanding from the last time I looked at the code was that
fsync does the right thing:

    The fsync() system call causes all modified data and
attributes of fd to
    be moved to a permanent storage device.  This normally results
in all in-
    core modified copies of buffers for the associated file to be
written to
    a disk.

This is probably the same issue that the hackers encountered on Darwin- namely fsync() flushes the kernel cache, but a further function call was needed to flush the hard drive buffers. This meets the standard's definition of fsync because the data is indeed moved to the device, but it happens to just be the device's buffer instead of non-volatile storage.


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