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Date: Mon, 10 Jan 2011 12:18:32 -0600 (CST)
From: Bob Friesenhahn <bfriesen@simple.dallas.tx.us>
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To: Attila Nagy <bra@fsn.hu>
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Cc: freebsd-fs@freebsd.org
Subject: Re: New ZFSv28 patchset for 8-STABLE
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On Mon, 10 Jan 2011, Attila Nagy wrote:
>
> Having this choice is good, and in this case enabling this makes sense for 
> me. I don't know any reasons about why you wouldn't use all of your L2ARC 
> space (apart from sparing the quickly wearing out flash space and move disk 
> heads instead), but I'm sure Brendan made this choice with a good reason.
> If you get an answer, please tell us. :)

Consider that your L2ARC device might be bandwidth limited to 
100-240MB/second while your main storage is capable of 1000MB or 
2000MB second sequential data transfer.  This a good reason to not 
simply put all data (which does not fit in normal ARC) into L2ARC. 
ARC is supposed to be adaptive ...

Bob
-- 
Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/