NFS Client error

[John Baldwin]

On Monday 08 March 2010 5:59:29 pm volker at vwsoft.com wrote:
> On 03/08/10 12:16, Giulio Ferro wrote:
> > Freebsd 8 stable amd64
> > 
> > It mounts different file systems by NFS (with locking) on a
> > data server directly connected (gigabit) to the server
> > 
> > Apache running in a several jails on those nfs folders.
> > 
> > Now and then I get huge slow-down. When I look in the logs
> > I get thousand of lines like these:
> > Mar  5 11:50:52 virt2 kernel: vm_fault: pager read error, pid 46487 
(httpd)
> > Mar  5 11:50:52 virt2 kernel: pid 46487 (httpd), uid 80: exited on
> > signal 11
> > 
> > 
> > What should I do?
> 
> Giulio,
> 
> it seems this is anyhow not related to network (nfs) operations. It's
> looking like a problem in the VM. I think it makes sense to have a look
> at the httpd.core file if the binary has been linked with debugging
> symbols turned on. Also I think at first, it may not hurt to look at
> vmstat -m output.
> 
> You may want to change ${subject} and post to stable@ to drive more
> attention to your problem.

That's not quite true.  If you take a page fault on a mmap'd file backed by
NFS (e.g. an executable or shared library) and an NFS READ RPC to satisfy the
page fault fails, then you could get this error.

-- 
John Baldwin