If the value of this attribute is 1 and the disk group becomes disabled, the node panics.

 

If the value of the attribute is 0 and the disk group becomes disabled, the following occurs:

 If the cluster has I/O fencing enabled, the DiskGroup resource is marked FAULTED.  This state results in the agent attempting to take the service group offline. As part of bringing the DiskGroup resource offline, the agent attempts to deport the disabled disk group. Even if disabled disk group fails to deport, the DiskGroup resource  enters a FAULTED state. This state enables the failover of the service group that includes the resource. To fail back the DiskGroup resource, manually deport the disk group after  restoring storage connectivity.

 

If the cluster does not use I/O fencing, a message is logged and the resource is reported ONLINE.


How to check the default value for the PanicSystemOnDGLoss:
eg. We see the value is set to 1 (enabled) by default.
 

# grep "boolean Panic" /etc/VRTSvcs/conf/config/types.cf
       boolean PanicSystemOnDGLoss = 1
 

How to change the default value for PanicSystemOnDGLoss:

# haconf -makerw
# haattr -default DiskGroup PanicSystemOnDGLoss 0
# haconf -dump -makero

 

Confirm that both the temporary and persistent definitions have been reset to 0:

 

 

# grep "boolean Panic" /etc/VRTSvcs/conf/config/types.cf
       boolean PanicSystemOnDGLoss = 0

 

How to change the value of this attribute for individual DiskGroup resources. In certain cases, it may be necessary to change this attribute to 1 for a few selected DiskGroup resources.

 

 

 

# haconf -dump -makero

In the Storage Foundation 5.1 Release, the default for PanicSystemOnDGLoss has been changed to "0", so that users are not surprised when VCS nodes panic when DGDISABLED condition is hit during a SAN outage.