From owner-freebsd-hackers@FreeBSD.ORG  Wed Apr 21 13:38:37 2004
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Date: Wed, 21 Apr 2004 16:38:32 -0400
To: Julian Elischer <julian@elischer.org>, hackers@freebsd.org
From: Garance A Drosihn <drosih@rpi.edu>
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Subject: Re: how to flush out cache.?
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At 12:23 PM -0700 4/21/04, Julian Elischer wrote:
>Ok so I have an application where I need to
>reread a file I have just written to ensure that it went to disk
>correctly..
>
>Other than reading a few GB of data, is there a way to flush
>out the cache copy of a file I've written?
>
>possibilities include:
>
>a file flag saying "don't keep a copy after it's written to disk"?
>a syscall discard_cached_blocks(fd);
>
>
>?
>any other suggestions?
>
>julian
>(BTW this would be for 4.x initially)

Hmm.  That means you couldn't use a 'snapshot' to force the
issue, right?  If you *could* use snapshots, you could close
the file, snapshot the partition, mount the snapshot, and
read the file from it's copy in the snapshot-filesystem.

-- 
Garance Alistair Drosehn            =   gad@gilead.netel.rpi.edu
Senior Systems Programmer           or  gad@freebsd.org
Rensselaer Polytechnic Institute    or  drosih@rpi.edu