Configuring DMP path restoration policies

DMP maintains a kernel thread that re-examines the condition of paths at a specified interval. The type of analysis that is performed on the paths depends on the checking policy that is configured.


The DMP path restoration thread does not change the disabled state of the path through a controller that you have disabled using vxdmpadm disable.

When configuring DMP path restoration policies, you must stop the path restoration thread, and then restart it with new attributes.

Use the vxdmpadm start restore command to configure one of the following restore policies. The policy will remain in effect until the restore thread is stopped or the values are changed using vxdmpadm settune command.

The interval attribute specifies how often the path restoration thread examines the paths. For example, after stopping the path restoration thread, the polling interval can be set to 400 seconds using the following command:

# vxdmpadm start restore interval=400

Starting with the 5.0MP3 release, you can also use the vxdmpadm settune command to change the restore policy, restore interval, and restore period. This method stores the values for these arguments as DMP tunables. The settings are immediately applied and are persistent across reboots. Use the vxdmpadm gettune to view the current settings.

If the vxdmpadm start restore command is given without specifying a policy or interval, the path restoration thread is started with the persistent policy and interval settings previously set by the administrator with the vxdmpadm settune command. If the administrator has not set a policy or interval, the system defaults are used. The system default restore policy is check_disabled. The system default interval is 300 seconds.


Decreasing the interval below the system default can adversely affect system performance.

More Information

Stopping the DMP path restoration thread

DMP tunable parameters