... the disks.
Wait for infinite loop and redirect the output to the (printed) log file.
The contents of the log file can be viewed in a desktop gadget or other commands that display it.
sendzero
Sends to all active monitors the 'setmax,waitzero' request action, to force flush the dirty cache.
Wait for zero dirty cache (currently for 90 seconds maximum).
bcache-backup.service is a sample service for systemd to handle bcacheMonitor on startup and shutdown of the operating system.