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Date: Tue, 26 Oct 2010 15:33:52 -0300 (ADT)
From: "Marc G. Fournier" <scrappy@hub.org>
To: freebsd-questions@freebsd.org
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Subject: fsync: Linux vs FreeBSD
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Someone recently posted on one of the PostgreSQL Blogs concerning fsync on 
Linux/Windows/Mac OS X, but failed to make any comments on any of the BSDs 
... the post has to do with how fsync works on the various OSs, and am 
curious as to whether or not this is something that also afflicts us:

http://rhaas.blogspot.com/2010/10/wal-reliability.html

>From reading our man page, I see no warnings similar to what the other OSs 
have, specifically:

Mac OS X: For applications that require tighter guarantees about the
           integrity of their data, Mac OS X provides the F_FULLFSYNC fcntl

Linux: If the underlying hard disk has write caching enabled, then the
        data may not really be on permanent storage when fsync() /
        fdatasync() return.

So, do we hide the fact, or are, in fact, not afflicted by this?

Thanks ...

----
Marc G. Fournier                        Hub.Org Hosting Solutions S.A.
scrappy@hub.org                                     http://www.hub.org

Yahoo:yscrappy    Skype: hub.org    ICQ:7615664    MSN:scrappy@hub.org