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Date: Thu, 24 Nov 2016 23:34:39 +0200
From: Konstantin Belousov <kostikbel@gmail.com>
To: Miroslav Lachman <000.fbsd@quip.cz>
Cc: freebsd-fs@FreeBSD.org
Subject: Re: how to clear FS cache
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On Thu, Nov 24, 2016 at 10:08:28PM +0100, Miroslav Lachman wrote:
> Is there a way to clear FS read cache between some benchmar runs?
> 
> I am looking for something like this on linux
> 
> $ sh -c "sync && echo 3 > /proc/sys/vm/drop_caches"

cd /your/mount/point
umount /your/mount/point

First command makes the mount point busy, so the unmount fails.  But before
failing, it flushes everything that is not used.