[ale] Fast NFS

Stephan Uphoff ups at tree.com
Sun Sep 12 12:54:01 EDT 2004


Time to tune your VM.

Basically you want to avoid having a lot of dirty pages. 
Clean your pages early and often ;-)

Not sure if you can reserve pages for exclusive kernel use - but
if you can - also increase this number.

With NFS you need clean pages to clean dirty pages.

Sorry - can't be more specific unless I look at the Linux sources or you
switch to NetBSD :-)

	Stephan

On Sun, 2004-09-12 at 09:49, Christopher Fowler wrote:
> I think it may be related to the ARM board.  It has only 32mb of mem and
> that is not much when compiling glibc.
> 
> Here is kernel log:
> 
> __alloc_pages: 0-order allocation failed (gfp=0x92/0)
> __alloc_pages: 0-order allocation failed (gfp=0x92/0)
> __alloc_pages: 0-order allocation failed (gfp=0x92/0)
> __alloc_pages: 0-order allocation failed (gfp=0x92/0)
> __alloc_pages: 0-order allocation failed (gfp=0x92/0)
> 
> Which tells me we are running out of memeory.
> 
> On Sat, 2004-09-11 at 23:54, Stephan Uphoff wrote:
> > On Sat, 2004-09-11 at 23:12, Christopher Fowler wrote:
> > > Funmy.
> > >
> > > I can't imagine a busty load.  I'm on a 100mbs switch and all I'm doing
> > > on the ARM is compiling GCC.  What else could be going on that the NFS
> > > server does not respond?  It is only serving up one share to one
> > > machine.  It is doing nothing else.
> >
> > Are you using NFS2 or NFS3 ?
> >
> > Have you tried to reduce the write/read size all the way down to 1024 ?
> >
> > Some network cards are just overwhelmed when a packet train for
> > a big NFS request/reply is coming in.
> >
> > What NIC are you using on the server?
> >
> > How big is the receive queue on your arm board?
> > Can the board get enough memory to replace the buffers used
> > by the received frames?
> >
> > As always a network sniffer is your best friend.
> >
> >
> > 	Stephan
> >
> >
> > >
> > >
> > > On Sat, 2004-09-11 at 21:29, Pete Hardie wrote:
> > > > On Sat, 11 Sep 2004 17:32:58 -0400, Stephan Uphoff <ups at tree.com> wrote:
> > > > > My guess is that IP fragmentation issues (packet loss under load, busty
> > > > > load .. ) are killing you. (You are using UDP right ?)
> > > >
> > > > "Busty load"???  When did they extend NFS to recognize porn? :->
> >
> > NFS 6 ?
> >
> > Not that I know of - but NFS 4 gained non persistent file handles for
> > the MS crowd :-( .... so they are definitely trying for mass appeal :-)
> >
> >
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> 
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