Add policy based automated repair of RAID logical volumes

The RAID plug-in for dmeventd now calls 'lvconvert --repair' to address failures
of devices in a RAID logical volume.  The action taken can be either to "warn"
or "allocate" a new device from any spares that may be available in the
volume group.  The action is designated by setting 'raid_fault_policy' in
lvm.conf - the default being "warn".

1 files changed, 24 insertions, 2 deletions

diff --git a/doc/example.conf.in b/doc/example.conf.in
index 72005e98..223f273d 100644
--- a/doc/example.conf.in
+++ b/doc/example.conf.in
@@ -522,9 +522,31 @@ activation {
     # "auto" - Use default value chosen by kernel.
     readahead = "auto"
 
+    # 'raid_fault_policy' defines how a device failure in a RAID logical
+    # volume is handled.  This includes logical volumes that have the following
+    # segment types: raid1, raid4, raid5*, and raid6*.
+    #
+    # In the event of a failure, the following policies will determine what
+    # actions are performed during the automated response to failures (when
+    # dmeventd is monitoring the RAID logical volume) and when 'lvconvert' is
+    # called manually with the options '--repair' and '--use-policies'.
+    #
+    # "warn"	- Use the system log to warn the user that a device in the RAID
+    # 		  logical volume has failed.  It is left to the user to run
+    #		  'lvconvert --repair' manually to remove or replace the failed
+    #		  device.  As long as the number of failed devices does not
+    #		  exceed the redundancy of the logical volume (1 device for
+    #		  raid4/5, 2 for raid6, etc) the logical volume will remain
+    #		  usable.
+    #
+    # "allocate" - Attempt to use any extra physical volumes in the volume
+    # 		  group as spares and replace faulty devices.
+    #
+    raid_fault_policy = "warn"
+
     # 'mirror_image_fault_policy' and 'mirror_log_fault_policy' define
-    # how a device failure affecting a mirror is handled.
-    # A mirror is composed of mirror images (copies) and a log.
+    # how a device failure affecting a mirror (of "mirror" segment type) is
+    # handled.  A mirror is composed of mirror images (copies) and a log.
     # A disk log ensures that a mirror does not need to be re-synced
     # (all copies made the same) every time a machine reboots or crashes.
     #