Re: Very poor NFS I/O

[MJ <mjose00%optusnet.com.au@localhost>]

On 28/02/2026 8:21 am, BERTRAND Joël wrote:
> Michael van Elst a écrit :
> > joel.bertrand%systella.fr@localhost (=?UTF-8?Q?BERTRAND_Jo=c3=abl?=) writes:
> >
> > > 	CPU is an i7-4770, main memory 16 GB. This server exports /srv and
> > > /home through NFS (V3/TCP, 128 threads, async) and disk I/O from NFS
> > > clients are very slow. Server load can raise until 110 or 120 during
> > > huge NFS access.
> >
> > Can you quantify what "slow" means? Any kind of benchmarks?
>
> 	Less than 2 MB/s.
>
> > The server load just shows that the NFS requests are distributed over
> > your server threads. But that is not related to any CPU utilization.
>
> 	I know. NFS process never reaches 35% of one core.
As per Michael's email, re: isolating disk and client, can you isolate which system it is slow serving to? I think that is important.

I note you use VMS, which is notorious for going out of "tune" if disks fragment or fill etc.

I would want to check each of the server's disks for performance to ensure they aren't failing - likewise the logs will help in this regard (perhaps install SMART to monitor them?)

What is your vfs.nfs.iothreads value?

Regards,
Max.