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From: Denys Vlasenko <vda.linux@googlemail.com>
To: Tino Keitel <tino.keitel@gmx.de>
Subject: Re: Strage buffer behaviour
Date: Mon, 12 Nov 2007 12:44:53 -0700
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References: <20071111183334.GA6770@dose.home.local>
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On Sunday 11 November 2007 11:33, Tino Keitel wrote:
> The dd command reads 100 MB from each partition two times in a row. It
> looks like sda1 and sda2 are not bufferd (the first 4 dd runs), but
> sda3 and sda4 are (the last 4 dd runs).
>
> The computer is a Mac mini with a 2,5" SATA hard disk. The first 2
> partitions contain EFI and MacOS X, and are unused in Linux. The last 2
> partitions are an ext3 partition for / and an LVM for the rest of the
> sytem.
>
> Any hints how the dd/buffering behaviour could be explained? The system
> was mostly idle, and the numbers are reproducible across reboots.

IIRC only mounted partitions' reads are cached.
--
vda
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