> 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. Regards, Simon