alarm: sync_freq
      on: mem.sync
  lookup: sum -1m of sync
   units: calls
   every: 1m
    warn: $this > 6
   delay: up 1m down 10m multiplier 1.5 max 1h
 summary: Sync system call frequency
    info: Number of sync() system calls. \
          Every call causes all pending modifications to filesystem metadata and \
          cached file data to be written to the underlying filesystems.
      to: silent