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

Andriy Gapon avg at freebsd.org
Wed Sep 15 20:05:20 UTC 2010


on 15/09/2010 23:00 Steven Hartland said the following:
> ----- Original Message ----- From: "Andriy Gapon" <avg at freebsd.org>
>> 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? :)
> 
> Ok given this a whirl, don't have the full results just yet but does seem that
> buf cache is not
> used at all?
> 
> Mem: 32M Active, 1378M Inact, 159M Wired, 120K Cache, 21M Buf, 5348M Free
> Swap: 4096M Total, 4096M Free

This was with sendfile enabled?

-- 
Andriy Gapon


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