Dears , CephFS mount succesful, however i encounted an issue about write file with error message "Operation not permitted". It happend even the file chmod 777, please help me to solve, thanks a lot! [root@vm-04 mycephfs]# df -Th Filesystem Type Size Used Avail Use% Mounted on /dev/mapper/centos-root xfs 46G 1.3G 44G 3% / devtmpfs devtmpfs 1.9G 0 1.9G 0% /dev tmpfs tmpfs 1.9G 0 1.9G 0% /dev/shm tmpfs tmpfs 1.9G 8.5M 1.9G 1% /run tmpfs tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup /dev/vda1 xfs 1014M 145M 870M 15% /boot tmpfs tmpfs 379M 0 379M 0% /run/user/0 192.168.100.7:6789,192.168.100.8:6789,192.168.100.9:6789:/ ceph 19G 0 19G 0% /mnt/mycephfs [root@vm-04 mycephfs]# [root@vm-04 mycephfs]# pwd /mnt/mycephfs [root@vm-04 mycephfs]# [root@vm-04 mycephfs]# ls -rlt total 0 -rw-r--r-- 1 root root 0 Apr 8 20:44 aa.txt -rw-r--r-- 1 root root 0 Apr 8 20:54 bb.txt [root@vm-04 mycephfs]# cp aa.txt cc.txt cp: error reading ‘aa.txt’: Operation not permitted cp: failed to extend ‘cc.txt’: Operation not permitted [root@vm-04 mycephfs]# [root@vm-04 mycephfs]# echo "123" > aa.txt -bash: echo: write error: Operation not permitted [root@vm-04 mycephfs]# [root@vm-04 mycephfs]#