Monit NFS share

Hello,

I have a little server that mount a NFS share from a NAS:

# cat /etc/fstab | grep nfs
192.168.1.2:/vol2/tvdata    /mnt/tvdata/    nfs    defaults    0 0

The problem is that sometimes it is not mounted at boot or the NAS could
reboot and I need to force the mount by "mount -a".

How could monitor the NFS share and mount if the share is not mounted?

I try this way:

check filesystem tvdata with path /mnt/tvdata
  if not exist then exec "/bin/mount -a"

But it does not work.

I will appreciate your help.

Kind regards.

-- 
Josu Lazkano