this is just a calculation - it has no alarm                                   
# we will use it in the next template to find                                    
# the hours remaining                                                            
                                                                                 
template: disk_fill_rate                                                         
      on: disk.space                                                             
      os: linux freebsd                                                          
   hosts: *                                                                      
families: *                                                                      
  lookup: min -10m at -50m unaligned of avail                                    
    calc: ($this - $avail) / (($now - $after) / 3600)                            
   every: 1m                                                                     
   units: GB/hour                                                                
    info: average rate the disk fills up (positive), or frees up (negative) space, for the last hour
                                                                                 
                                                                                 
# calculate the hours remaining                                                                                                                                                                                                                                
# if the disk continues to fill                                                  
# in this rate                                                                   
                                                                                 
template: out_of_disk_space_time                                                 
      on: disk.space                                                             
      os: linux freebsd                                                          
   hosts: *                                                                      
families: *                                                                      
    calc: ($disk_fill_rate > 0) ? ($avail / $disk_fill_rate) : (inf)             
   units: hours                                                                  
   every: 10s                                                                    
    warn: $this > 0 and $this < (($status >= $WARNING)  ? (48) : (8))            
    crit: $this > 0 and $this < (($status == $CRITICAL) ? (24) : (2))            
   delay: down 15m multiplier 1.2 max 1h                                         
    info: estimated time the disk will run out of space, if the system continues to add data with the rate of the last hour
      to: sysadmin