by Jeff Garzik[permalink] [raw]
saeed bishara wrote:
>>>> Are you using TCP? Are you using NFSv4, or an older version?
>>> I'm using NFSv3/UDP.
>> IMO, you definitely want TCP and NFSv4. Much better network behavior,
>> with some of the silly UDP limits (plus greatly improved caching
>> behavior, due to v4 delegations).
> the clients of my system going to be embedded system with low
> performance cpus and I need UDP as it needs less cpu power.
TCP + fewer revalidations + greater local pagecache activity
uses less cpu power than
UDP + revalidations + rx/tx network activity
>>> when I run local dd with bs=4K, I can see that the average IO size is
>>> more than 300KB.
>> Read-ahead is easier in NFSv4, because the client probably has the file
>> delegated locally, and has far less need to constantly revalidate file
> I'll check that.
> but what about the server side? why the issued IO's are only as twice
> as the size of the NFS requests?
No idea. I bet the source code can tell you :)
2007-12-27 15:38:58[permalink] [raw]
> I bet
> TCP + fewer revalidations + greater local pagecache activity
> uses less cpu power than
> UDP + revalidations + rx/tx network activity
what do you mean by revalidations?
the workload of the client going to be large sequential IO's, so does
the local pagecache is necessary for this case?