zfs very poor performance compared to ufs due to lack of cache?

[Steven Hartland]

----- Original Message ----- 
From: "Andriy Gapon" <avg at freebsd.org>
To: "Steven Hartland" <killing at multiplay.co.uk>
Cc: <freebsd-fs at freebsd.org>; "Pawel Jakub Dawidek" <pjd at freebsd.org>; "jhell" <jhell at 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?

    Regards
    Steve

================================================
This e.mail is private and confidential between Multiplay (UK) Ltd. and the person or entity to whom it is addressed. In the event of misdirection, the recipient is prohibited from using, copying, printing or otherwise disseminating it or any information contained in it. 

In the event of misdirection, illegible or incomplete transmission please telephone +44 845 868 1337
or return the E.mail to postmaster at multiplay.co.uk.