Poor Fedora Core 1's NFS performance and how to tune it?

[WipeOut]

Guolin Cheng wrote:

> Hi,
>
>  
>
>  We installed about tens of Fedora Core 1 machines, But then found 
> that the FC1 NFS speed is greatly slow down contrasted with our 
> previous Redhat 8.0.
>
> Our FC1's nfs speed is now at 6MB/s, while original Redhat 8.0's speed 
> is at 10MB/s. For both operation systems I did no special NFS tunings.
>
>  
>
> Our Original environment RH8 environment is:  Redhat 8.0, 2.4.20 
> vanilla kernel without "nfs over tcp" support.
>
>  
>
> Our current environment is: Fedora Core 1, 2.4.25 vanilla kernel, with 
> "nfs over tcp" kernel support enabled.
>
>  
>
> But it seems that the nfs performance has no directly relationship 
> with "nfs over tcp" in kernel configuration. The reason is:
>
>  
>
> I use both RH8|FC1 clients to connect to FC1 nfs server, connections 
> set to either "nfs over udp" or "nfs over tcp", the speed is about the 
> same, ranged from 6.09MB/s to 6.30MB/s.
>
>  
>
> But from original RH8 nfs clients to RH8 nfs servers, the speed is at 
> 10MB-11MB/s, since I compiled no "nfs over tcp" support for RH8 
> kernel, the nfs connection is based on UDP traffic only.
>
>  
>
> Personally I prefer "nfs over tcp" feature enabled. Since tcp traffic 
> is more reliable and bring less trouble to Ops, even it is a little 
> less efficient.
>
>  
>
> I tried to increase the NFS read/write size from 1024/1024, to 
> 4096/4096, to 8192/8192, but that makes almost no difference at all.
>
>  
>
> Any suggestions/opinions on why FC1's nfs performance is downgraded? 
> Or I need to adjust any other parameters?
>
>  
>
> Thanks.
>
> --Guolin Cheng
>
>  
>
Are you testing reads or writes?

If its writes I found that where higher speed is required you need to 
enable "async" writes which will make it a lot faster..

Later..