Terrible NFS4 performance: FreeBSD 9.1 + UFS/ZFS + AWS EC2

[Rick Macklem]

Berend de Boer wrote:
> >>>>> "Julian" == Julian Elischer <julian at freebsd.org> writes:
> 
>     Julian> Recent evidence with AWS is suggesting that the
>     Julian> NOADAPTIVE_XXX options in the XENHVM kernel are now
>     Julian> seriously hindering AWS performance all over the place.
>     Julian> make sure you have tried with these options removed.
> 
> Julian, on the same machine nfs3 is better than Linux, and nfs4 is
> terrible.
> 
All I could tell from the packet trace is that it is doing a massive
number of lookups. I have no idea why the client does this, but it
could possibly be the way the system is storing directory modify times
and the change attribute (which is kinda like a modify time, in that
it changes whenever a file's data or metadata changes, for NFSv4 only).

I know absolutely nothing about this virtualized environment, so all
I can suggest is trying "real hardware" to see if the same behaviour
occurs when the server is running on a real hardware box.

rick

> 
> --
> All the best,
> 
> Berend de Boer
> 
> 
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