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