Le 13/05/2020 à 15:36, Patrick Bégou a écrit :
Le 13/05/2020 à 07:32, Simon Matter via CentOS a écrit :
Le 12/05/2020 à 16:10, James Pearson a écrit :
Patrick Bégou wrote:
Hi,
I need some help with NFSv4 setup/tuning. I have a dedicated nfs server (2 x E5-2620 8cores/16 threads each, 64GB RAM, 1x10Gb ethernet and 16x 8TB HDD) used by two servers and a small cluster (400 cores). All the servers are running CentOS 7, the cluster is running CentOS6.
Time to time on the server I get:
kernel: NFSD: client xxx.xxx.xxx.xxx testing state ID with incorrect client ID
And the client xxx.xxx.xxx.xxx freeze whith:
kernel: nfs: server xxxxx.legi.grenoble-inp.fr not responding, still trying kernel: nfs: server xxxxx.legi.grenoble-inp.fr OK kernel: nfs: server xxxxx.legi.grenoble-inp.fr not responding, still trying kernel: nfs: server xxxxx.legi.grenoble-inp.fr OK
There is a discussion on RedHat7 support about this but only open to subscribers. Other searches with google do not provide useful information.
Do you have an idea how to solve these freeze states ?
More generally I would be really interested with some advice/tutorials to improve NFS performances in this dedicated context. There are so many [different] things about tuning NFS available on the web that I'm a little bit lost (the opposite of the previous question). So if some one has "the tutorial"...;-)
How many nfsd threads are you running on the server? - current count will be in /proc/fs/nfsd/threads
James Pearson
Hi James,
Thanks for your answer. I've configured 24 threads (for 16 hardware cores/ 32Threads on the NFS server with this processors)
But it seams that there are buffer setup to modify too when increasing the threads number... It is not done.
Load average on the server is below 1....
I'd be very careful with higher thread numbers than physical cores. NFS threads and so called CPU hyper/simultaneous threads are quite different things and it can hurt performance if not configured correctly.
So you suggest to limit the setup to 16 daemons ? I'll try this evening.
Setting 16 daemons (the number of physical cores) do not solve this problem. Moreover I saw a document (but old) provided by DELL to optimize NFS servers performances in HPC context and they suggest to use... 128 daemons on a dedicated poweredge server. :-\
I saw that it is always the same client showing the problem (a large fat node), may be I must investigate on the client side more than on the serveur side.
Patrick