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Administering an Oracle® Solaris Cluster 4.4 Configuration

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Updated: March 2019
 
 

How to Change the Default Global Fencing Protocol Settings for All Storage Devices

You can turn fencing on or off globally for all storage devices connected to a cluster. The default fencing setting of a single storage device overrides the global setting when the device's default fencing is set to pathcount, prefer3, or nofencing. If the default fencing setting of a storage device is set to global, the storage device will use the global setting. For example, if a storage device has the default setting pathcount, the setting will not change if you use this procedure to change the global SCSI protocol settings to prefer3. You must use the How to Change the Fencing Protocol for a Single Storage Device procedure to change the default setting of a single device.


Caution

Caution  -  If fencing is turned off 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 fencing off. Fencing can be turned off if the shared storage device does not support the SCSI protocol or if you want to allow access to the cluster's storage from hosts outside the cluster.


To change the default fencing setting for a quorum device, you must unconfigure the device, change the fencing setting, and reconfigure the quorum device. If you plan to turn fencing off and back on regularly for devices that include quorum devices, consider configuring quorum through a quorum server service to eliminate interruptions in quorum operation.

The phys-schost# prompt reflects a global-cluster prompt. Perform this procedure on a global cluster.

This procedure provides the long forms of the Oracle Solaris Cluster commands. Most commands also have short forms. Except for the long and short forms of the command names, the commands are identical.

  1. Assume the root role or a role that provides solaris.cluster.modify authorization.
  2. Set the fencing protocol for all storage devices that are not quorum devices.
    cluster set -p global_fencing={pathcount | prefer3 | nofencing | nofencing-noscrub}
    -p global_fencing

    Sets the current global default fencing algorithm for all shared devices.

    prefer3

    Uses the SCSI-3 protocol for devices with more than two paths.

    pathcount

    Determines the fencing protocol by the number of DID paths that are attached to the shared device. The pathcount setting is used for quorum devices.

    nofencing

    Turns fencing off by setting the fencing status for all storage devices.

    nofencing-noscrub

    Scrubbing the device ensures that the device is cleared of all persistent SCSI reservation information and allows access to the storage from systems outside the cluster. Use the nofencing-noscrub option only for storage devices that have severe problems with SCSI reservations.

Example 43  Setting the Default Global Fencing Protocol Settings for All Storage Devices

The following example sets the fencing protocol for all storage devices on the cluster to the SCSI-3 protocol.

# cluster set -p global_fencing=prefer3