NFS Performance issue against NetApp

[Rick Macklem]

Marc G. Fournier wrote:
> FYI … I just installed Solaris 11 onto the same hardware and ran the
> same test … so far, I'm seeing:
> 
> Linux @ ~30s
> Solaris @ ~44s
> 
> OpenBSD @ ~200s
> FreeBSD @ ~240s
> 
> I've even tried FreeBSD 8.3 just to see if maybe its as 'newish' issue
> … same as 9.x … I could see Linux 'cutting corners', but
> Oracle/Solaris too … ?
> 
The three client implementations (BSD, Linux, Solaris) were developed
independently and, as such, will all implement somewaht different
caching algorithms (the RFCs specify what goes on the wire, but say
little w.r.t. client side caching).

I have a attached a patch that might be useful for determining if
the client side buffer cache consistency algorithm in FreeBSD is
causing the slow startup of jboss. Do not run this patch on a
production system, since it pretty well disables all buffer cache
coherency (ie. if another client modifies a file, the patched client
won't notice and will continue to cache stale file data).

If the patch does speed up startup of jboss significantly, you can
use the sysctl:
 vfs.nfs.noconsist
to check for which coherency check is involved by decreasing the
value for the sysctl by 1 and then trying a startup again. (When
vfs.nfs.noconsist=0, normal cache coherency will be applied.)

I have no idea if buffer cache coherency is a factor, but trying
the attached patch might determine if it is.

Note that you have never posted updated "nfsstat -c" values.
(Remember that what you posted indicated 88 RPCs, which seemed
 bogus.) Finding out if FreeBSD does a lot more of certain RPCs
that Linux/Solaris might help isolate what is going on.

rick

> On 2013-05-03, at 04:50 , Mark Felder <feld at feld.me> wrote:
> 
> > On Thu, 02 May 2013 18:43:17 -0500, Marc G. Fournier
> > <scrappy at hub.org> wrote:
> >
> >> Hadn't thought to do so with Linux, but …
> >> Linux ……. 20732ms, 20117ms, 20935ms, 20130ms, 20560ms
> >> FreeBSD .. 28996ms, 24794ms, 24702ms, 23311ms, 24153ms
> >
> > Please make sure both platforms are using similar atime settings. I
> > think most distros use ext4 with diratime by default. I'd just do
> > noatime on both platforms to be safe.
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