Failfast Mechanism

The failfast mechanism detects a critical problem on a global-cluster node.

When the critical problem is located in a node, Oracle Solaris Cluster forcibly shuts down the node. Oracle Solaris Cluster then removes the node from cluster membership.

If a node loses connectivity with other nodes, the node attempts to form a cluster with the nodes with which communication is possible. If that set of nodes does not form a quorum, Oracle Solaris Cluster software halts the node and “fences” the node from the shared disks, that is, prevents the node from accessing the shared disks. Fencing is a mechanism that is used by the cluster to protect the data integrity of a shared disk during split-brain situations. By default, the scinstall utility in Typical Mode leaves global fencing enabled.

You can turn off fencing for selected disks or for all disks.

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Caution  - If you turn off fencing under the wrong circumstances, your data can be vulnerable to corruption during application failover. Examine this data corruption possibility carefully when you are considering turning off fencing. If your shared storage device does not support the SCSI protocol, such as a Serial Advanced Technology Attachment (SATA) disk, or if you want to allow access to the cluster's storage from nodes outside the cluster, turn off fencing.

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If one or more cluster-specific daemons die, Oracle Solaris Cluster software declares that a critical problem has occurred. When this occurs, Oracle Solaris Cluster shuts down and removes the node where the problem occurred.

When a cluster-specific daemon that runs on a node fails and the node panics, a message similar to the following is displayed on the console.

panic[cpu1]/thread=2a10007fcc0: Failfast: Aborting because "pmfd" died in zone "global" (zone id 0)
35 seconds ago.
409b8 cl_runtime:__0FZsc_syslog_msg_log_no_argsPviTCPCcTB+48 (70f900, 30, 70df54, 407acc, 0)
%l0-7: 1006c80 000000a 000000a 10093bc 406d3c80 7110340 0000000 4001 fbf0