[PVFS-users] Poor performance

[Rob Ross]

Jon,

What's the network in the system?  We're betting on fast ethernet :).

Rob

Robert Latham wrote:
> On Tue, Jun 07, 2005 at 10:06:38AM +0100, Jon Combe wrote:
> 
>>The file is 1549403622 bytes. As far as I can see (via top) nothing
>>else is happening on the box.
> 
> 
> Comparing the time to operate on 1.5 GBytes locally vs. operating on that
> same 1.5 GBytes remotely isn't exactly a fair comparison.   Perhaps I'm
> making a bad assumption about your topology, but you have clients and
> servers on separate machines, right?  If so, there's no way around the
> fact you have to move 1.5 GBytes over the network in the pvfs case.
>  
> 
>>Well thats fair enough, but are you saying the sort of performance
>>difference I'm seeing above is normal for PVFS?
> 
> 
> With the large blocksizes you were seeing just over 10 Mbytes/sec.
> that's pretty resaonable for single-node access to PVFS over fast
> ethernet.  That's pretty close to the maximum bandwidth you'll get out
> of fast ethernet.  With the default blocksize you were still getting 3
> MBytes/sec.   I think that's pretty typical performance for small
> blocksize transfers over ethernet.  
> 
> Like I said, I don't know the exact details of your setup, so let me
> know if i've gone off on a faulty assumption here. 
> 
> ==rob
>