RAID Monitoring Parameters and Events

The following table lists additional command line parameters that can be passed to

mdadm at startup.

Table C-1. Parameters for mdadm in Monitor Mode

Long form	Short Form	Description
--mail	-m	Provide mail address to email alerts or failures to.
--program or --alert	-p	Provide program to run when an event is detected.
--delay	-d	Seconds of delay between polling state. Default is 60s.
--config	-c	Specify a different config file.
--scan	-s	Find mail-address/program settings in config file.
--oneshot	-1	Check for degraded arrays and then exit.
--test	-t	Generate a Test Message event against each array at startup.
--syslog	-y	Cause all events to be reported through syslog. The messages have facility of ’daemon’ and varying priorities.
--increment	-r	Give a percentage increment. mdadm will generate RebuildNN events with the NN indicating the percentage at which the rebuild event had happened.
--daemonise	-f	Run as background daemon if monitoring.
--pid-file	-i	Write the PID of the daemon process to a specified file.
--no-sharing	N/A	This inhibits the functionality for moving spare drives between arrays.

Note: The mdmonitor service has to be re-started if mdmonitor.service or the mdadm.conf file is changed.

The following table presents all the events that are reported by the mdadm monitor:

Table C-2. Monitoring Events

Event Name	Description
DeviceDisappeared	An MD array previously configured no longer exists.
RebuildStarted	An MD array started reconstruction.
RebuildNN	NN is a 2-digit number that indicates rebuild has passed that many percent of the total. For example, Rebuild50 will trigger an event when 50% of rebuild has completed.
RebuildFinished	An MD array has completed rebuild.
Fail1	An active component of an array has been marked faulty.
FailSpare1	A spare drive that was being rebuilt to replace a faulty device has failed.
SpareActive	A spare drive that was being rebuilt to replace a fault device is rebuilt and active.
NewArray	A new MD array has been detected in /proc/mdstat.
DegradedArray1	A newly discovered array appears to be degraded.
MoveSpare	A spare drive has been moved from one array in a spare group to another array to replace a failed drive. Both arrays are labeled with the same spare group.
SparesMissing1	The spare device(s) does not exist in comparison to the config file when the MD array is first discovered.
TestMessage1	Discovered new array while the --test flag was used.

Note: 1 The events indicated cause an email to be sent. These can also be sent to the syslog file.