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From: Christopher Sean Hilton <chris@vindaloo.com>
To: Kevin Oberman <oberman@es.net>
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Date: Tue, 28 Nov 2006 16:41:11 -0500
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Cc: FreeBSD Stable <freebsd-stable@FreeBSD.ORG>
Subject: Re: Problems unmounting/fssyncking extern UFS filesystem
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On Tue, 2006-11-28 at 11:51 -0800, Kevin Oberman wrote:

[ ... ]

> The magic phrase is "buffer cache has been flushed". In the real world
> of discs with cache there is no way to be certain when the data is
> REALLY on the disc. That is why things get clobbered if the power is
> cycled to the disc too soon after syncing and why a sleep (or typing
> sync three times) is still a good idea and probably always will be.
> 

Please understand that this is an honest question but isn't that true
only of IDE heritage drives. E.g. If a SCSI drive with Tagged Queuing
says that the the bits have been written doesn't it mean that the bits
have really been written?

-- Chris