# -----------------------------------------------------------------------------
# low disk space

# checking the latest collected values
# raise an alarm if the disk is low on
# available disk space

template: disk_space_usage
      on: disk.space
families: *
    calc: $used * 100 / ($avail + $used)
   units: %
   every: 1m
    warn: $this > (($status >= $WARNING ) ? (80) : (90))
    crit: $this > (($status == $CRITICAL) ? (90) : (98))
   delay: up 1m down 15m multiplier 1.5 max 1h
    info: current disk space usage
      to: sysadmin

template: disk_inode_usage
      on: disk.inodes
families: *
    calc: $used * 100 / ($avail + $used)
   units: %
   every: 1m
    warn: $this > (($status >= $WARNING)  ? (80) : (90))
    crit: $this > (($status == $CRITICAL) ? (90) : (98))
   delay: up 1m down 15m multiplier 1.5 max 1h
    info: current disk inode usage
      to: sysadmin


# -----------------------------------------------------------------------------
# disk fill rate

# calculate the rate the disk fills
# use as base, the available space change
# during the last hour

# 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
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
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


# -----------------------------------------------------------------------------
# disk congestion

# raise an alarm if the disk is congested
# by calculating the average disk utilization
# for the last 10 minutes

template: 10min_disk_utilization
      on: disk.util
families: *
  lookup: average -10m unaligned
   units: %
   every: 1m
   green: 90
     red: 98
    warn: $this > $green * (($status >= $WARNING)  ? (0.7) : (1))
    crit: $this > $red   * (($status == $CRITICAL) ? (0.7) : (1))
   delay: down 15m multiplier 1.2 max 1h
    info: the percentage of time the disk was busy, during the last 10 minutes
      to: sysadmin


# raise an alarm if the disk backlog
# is above 1000ms (1s) per second
# for 10 minutes
# (i.e. the disk cannot catch up)

template: 10min_disk_backlog
      on: disk.backlog
families: *
  lookup: average -10m unaligned
   units: ms
   every: 1m
   green: 2000
     red: 5000
    warn: $this > $green * (($status >= $WARNING)  ? (0.7) : (1))
    crit: $this > $red   * (($status == $CRITICAL) ? (0.7) : (1))
   delay: down 15m multiplier 1.2 max 1h
    info: average of the kernel estimated disk backlog, for the last 10 minutes
      to: sysadmin
