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Subject: Re: [linux-lvm] Re: [Announce] device-mapper beta3 (fast snapshots)
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Joe Thornber <joe@fib011235813.fsnet.co.uk>
Cc: linux-lvm@sistina.com, Andrew Theurer <habanero@us.ibm.com>,
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On Wed, 2002-07-17 at 11:31, Joe Thornber wrote:
> On Tue, Jul 16, 2002 at 01:27:24PM -0400, Chris Mason wrote:
> > Some IDE drives ignore commands to turn off the write back cache, or
> > turn it back on when load gets high.
> 
> I'm amazed hardware manufacturers would dare to do such a thing - I
> guess I'm naive.

Its not explicitly against the spec. Some of them also like to make
"cache flush" a no-op too. The next generation of ATA is supposed to add
explicit "direct to media" write command facilities

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