Hi, we sometimes loose access to our cephfs mount and get permission denied if we try to cd into it. This happens apparently only on some of our HPC cephfs-client nodes (fs mounted via kernel client) when they are busy with calculation and I/O. When we then manually force unmount the fs and remount it, everything is working again. This is the dmesg output of the affected client node: <https://pastebin.com/z5wxUgYS> All HPC clients and ceph servers are running CentOS 7.7 with the same kernel: $ uname -a Linux apollo-08.local 3.10.0-1062.12.1.el7.x86_64 #1 SMP Tue Feb 4 23:02:59 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux and all are running ceph version 14.2.7 $ ceph -v ceph version 14.2.7 (3d58626ebeec02d8385a4cefb92c6cbc3a45bfe8) nautilus (stable) Maybe someone has an idea what goes wrong, and how we can fix/avoid this. Thanks Dietmar -- _________________________________________ D i e t m a r R i e d e r, Mag.Dr. Innsbruck Medical University Biocenter - Institute of Bioinformatics Email: dietmar.rieder@i-med.ac.at Web: http://www.icbi.at