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Date: Fri, 28 Oct 2011 10:16:42 -0500 (CDT)
From: Bob Friesenhahn <bfriesen@simple.dallas.tx.us>
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To: Dennis Glatting <freebsd@penx.com>
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Cc: freebsd-fs@freebsd.org
Subject: Re: ZFS across controllers
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On Fri, 28 Oct 2011, Dennis Glatting wrote:

> This seems like a stupid question but is there any significant performance 
> problems with a ZFS RAIDz volume served across multiple controllers?

No.  Available IOPS will be dominated/limited by whichever controller 
and disks are slowest to respond.

> I have seen two cases that confuse me. First, performance degrades over time. 
> I have read there was previously a prefetch bug but it has been fixed. I also 
> recently turned off prefetching to test (no opinion yet).

In what way is performance degrading?  What means are you using to 
evaluate performance?

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