You can stop the execution of Linux FailSafe on a systemwide basis, on all the nodes in a cluster, or on a specified node only.
Deactivating a node or a cluster is a complex operation that involves several steps and can take several minutes. Aborting a deactivate operation can leave the nodes and the resources in an intended state.
When deactivating HA services on a node or for a cluster, the operation may fail if any resource groups are not in a stable clean state. Resource groups which are in transition will cause any deactivate HA services command to fail. In many cases, the command may succeed at a later time after resource groups have settled into a stable state.
After you have successfully deactivated a node or a cluster, the node or cluster should have no resource groups and all HA services should be gone.
Serially stopping HA services on every node in a cluster is not the same as stopping HA services for the entire cluster. If the former case, an attempt is made to keep resource groups online and highly available while in the latter case resource groups are moved offline, as described in the following sections.
When you stop HA services, the Linux FailSafe daemons perform the following actions:
A shutdown request is sent to Linux FailSafe (FSD)
FSD releases all resource groups and puts them in ONLINE-READY state
All nodes in the cluster in the configuration database are disabled (one node at a time and the local node last)
Linux FailSafe waits until the node is removed from cluster membership before disabling the node
The shutdown is successful only when all nodes are not part of cluster membership
CMOND receives notification from the configuration database when nodes are disabled
The local CMOND sends SIGTERM to all HA processes and IFD.
All HA processes clean up and exit with “don't restart” code
All other CMSD daemons remove the disabled node from the cluster membership
The operation of deactivating a node tries to move all resource groups from the node to some other node and then tries to disable the node in the cluster, subsequently killing all HA processes.
When HA services are stopped on a node, all resource groups owned by the node are moved to some other node in the cluster that is capable of maintaining these resource groups in a highly available state. This operation will fail if there is no node that can take over these resource groups. This condition will always occur if the last node in a cluster is shut down when you deactivate HA services on that node.
In this circumstance, you can specify the force option to shut down the node even if resource groups cannot be moved or released. This will normally leave resource groups allocated in a non-highly-available state on that same node. Using the force option might result in the node getting reset. In order to guarantee that the resource groups remain allocated on the last node in a cluster, all online resource groups should be detached.
If you wish to move resource groups offline that are owned by the node being shut down, you must do so prior to deactivating the node.
The operation of deactivating a cluster attempts to release all resource groups and disable all nodes in the cluster, subsequently killing all HA processes.
When a cluster is deactivated and the Linux FailSafe HA services are stopped on that cluster, resource groups are moved offline or deallocated. If you want the resource groups to remain allocated, you must detach the resource groups before attempting to deactivate the cluster.
Serially stopping HA services on every node in a cluster is not the same as stopping HA services for the entire cluster. If the former case, an attempt is made to keep resource groups online and highly available while in the latter case resource groups are moved offline.
To stop Linux FailSafe services using the Cluster Manager GUI, perform the following steps:
On the left side of the display, click on the “Nodes & Cluster” category.
On the right side of the display click on the “Stop FailSafe HA Services” task link to launch the task.
Enter the selected inputs.
Click on “OK” at the bottom of the screen to complete the task.
To deactivate Linux FailSafe in a cluster and stop Linux FailSafe processing, use the following command:
cmgr> stop ha_services [on node A] [for cluster B][force] |