Hello again,
On Analysis configuration page, I see a warning message stating as follows:
By default each Check_MK site has it’s own temporary filesystem (a ramdisk) mounted to [SITE]/tmp. In case the mount is not possible Check_MK starts without this temporary filesystem.
Even if this is possible, it is not recommended to use Check_MK this way because it may reduce the overall performance of Check_MK.
monitor WARN: The temporary filesystem is not mounted. Your installation may work with degraded performance. (!)
The /etc/fstab has the temporary filesystem line added already by the OMD but this isn’t reflecting on the WATO even after a reboot.
tmpfs /opt/omd/sites/monitor/tmp tmpfs noauto,user,mode=755,uid=monitor,gid=monitor 0 0
I had this same situation on my development server, and sorted it few months back but I couldn’t recall what I did on it (forgot completely :no_mouth).
If anyone could shed some light on this, that would be much helpful. 
Thanks in advance.