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. Patrick