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Date: Wed, 15 Sep 2010 20:48:05 +0300
From: Andriy Gapon <avg@freebsd.org>
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To: Steven Hartland <killing@multiplay.co.uk>
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Cc: freebsd-fs@freebsd.org
Subject: Re: zfs very poor performance compared to ufs due to lack of cache?
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on 15/09/2010 20:38 Steven Hartland said the following:
> ----- Original Message ----- From: "Andriy Gapon" <avg@freebsd.org>
> To: "Steven Hartland" <killing@multiplay.co.uk>
> Cc: <freebsd-fs@freebsd.org>; "Pawel Jakub Dawidek" <pjd@freebsd.org>; "jhell"
> <jhell@DataIX.net>
> Sent: Wednesday, September 15, 2010 5:00 PM
> Subject: Re: zfs very poor performance compared to ufs due to lack of cache?
> 
> 
>> on 15/09/2010 18:04 Steven Hartland said the following:
>>> Hmm, so taking a different track on the issue is the a way to make sendfile use
>>> data
>>> directly from ARC instead of having to copy it first?
>>
>> Or even try the opposite, if your version of ZFS permits it.
>> You can set primarycache=metadata on the filesystem where you have the data that
>> you serve via sendfile.  With that setting it shouldn't get cached in ARC, but it
>> should be still cached in VM cache, so you should get UFS-like behavior.
>>
>> Will you test it? :)
> 
> Interesting, the same for secondarycache?

Do you have it (L2ARC) ?
Anyways, L2ARC is not in RAM.

-- 
Andriy Gapon