Ext3 behavior on power failure

[armangau_philippe at emc.com]

In my case the disk cache is not a  problem - We use an emc disk array
the write cache is protected - 
Once the data has made over the disk array we can assume it is safe - 
Thx 
Philippe  

-----Original Message-----
From: John Anthony Kazos Jr. [mailto:jakj at j-a-k-j.com] 
Sent: Wednesday, March 28, 2007 9:17 AM
To: Jan Kara
Cc: wheeler, richard; armangau, philippe; ext3-users at redhat.com;
linux-ext4 at vger.kernel.org; csar at stanford.edu
Subject: Re: Ext3 behavior on power failure

>  If you fsync() your data, you are guaranteed that also your data are
> safely on disk when fsync returns. So what is the question here?

Pardon a newbie's intrusion, but I do know this isn't true. There is a 
window of possible loss because of the multitude of layers of caching, 
especially within the drive itself. Unless there is a
super_duper_fsync() 
that is able to actually poll the hardware and get a confirmation that
the 
internal buffers are purged?