mdevents plugin¶

See this section in the full configuration reference

The * mdevents * plugin collects status changes from md (Linux software RAID) devices.

RAID arrays are meant to allow users/administrators to keep systems up and running, in case of common hardware problems (disk failure). Mdadm is the standard software RAID management tool for Linux. It provides the ability to monitor "metadata event" occurring such as disk failures, clean-to-dirty transitions, and etc. The kernel provides the ability to report such actions to the userspace via sysfs, and mdadm takes action accordingly with the monitoring capability. The mdmon polls the /sys looking for changes in the entries array_state, sync_action, and per disk state attribute files. This is meaningful for RAID1, 5 and 10 only.

Mdevents plugin is based on gathering RAID array events that are written to syslog by mdadm. After registering an event, it can send a collectd notification that contains mdadm event's data. Event consists of event type, raid array name and, for particular events, name of component device.

Example message:

Jan 17 05:24:27 pc1 mdadm[188]: NewArray event detected on md device /dev/md0

Plugin also classifies gathered event. This means that a notification will have a different severity {OKAY, WARNING, FAILURE} for particular mdadm event.

For proper work, mdevents plugin needs syslog and mdadm utilities to be present on the running system. Otherwise it will not be compiled as a part of collectd.

Synopsis:

<Plugin mdevents>
  Event ""
  IgnoreEvent False
  Array ""
  IgnoreArray False
</Plugin>

Plugin configuration:

Mdevents plugin's configuration is mostly based on IgnoreList, which is a collectd's utility. User can specify what particular events/RAID arrays lie in his interest. Setting of IgnoreEvent/IgnoreArray booleans won't take effect if Event/Array config lists are empty - plugin will accept entry anyway.

Options:

Event "EventName"

Names of events to be monitored, separated by spaces. Possible events include:

Event Name | Class of event ------------------+--------------- DeviceDisappeared | FAILURE RebuildStarted | OKAY RebuildNN | OKAY RebuildFinished | WARNING Fail | FAILURE FailSpare | WARNING SpareActive | OKAY NewArray | OKAY DegradedArray | FAILURE MoveSpare | WARNING SparesMissing | WARNING TestMessage | OKAY

User should set the events that should be monitored as a strings separated by spaces, for example Events "DeviceDisappeared Fail DegradedArray".

IgnoreEvent false|true

If IgnoreEvent is set to true, events specified in Events will be ignored. If it's false, only specified events will be monitored.

Array arrays

User can specify an array or a group of arrays using regexp. Plugin will accept only RAID arrays names that start with "/dev/md".

IgnoreArray false|true

If IgnoreArray is set to true, arrays specified in Array will be ignored. If it's false, only specified events will be monitored.