I understand we have a parameter "FSMOUNTStatus". But this one is only used to show if the FILESYSTEM is mounted or not.
There's a chance that the FILESYTEM is mounted but not available in the system to use.
1.Mount a filesystem called “/test”.
$mount -t nfs 18.104.22.168:/tmp /test
Filesystem 1K-blocks Used Available Use% Mounted on
18134344 7402360 9810796 44% /
tmpfs 506540 0 506540 0% /dev/shm
/dev/sda1 495844 32586 437658 7% /boot
22.214.171.124:/tmp 27228160 4802560 21036032 19% /test
/dev/mapper/vg_linux6-lv_root on / type ext4 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw)
/dev/sda1 on /boot type ext4 (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
126.96.36.199:/tmp on /test type nfs (rw,vers=4,addr=188.8.131.52,clientaddr=184.108.40.206)
2. Disable the Network Interface of the filesystem “/test” which binding to.
3. "df" command no longer show it however the "mount -v" command still show it.
4. In this case the FILESYSTEM KM will not report the /test is no longer available. the "FSMOUNTStatus" parameter still keep giving OK data point.