PRIMECLUSTER Wizard for NAS (PRIMEQUEST) 4.2 Configuration and Administration Guide - Linux -

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Appendix B Turning of the control facility for the NAS-Cluster

In PRIMECLUSTER Wizard for NAS, it is monitored to the NAS-Cluster accessible by the ping command. When ping doesn't respond (It is not possible to access it), PRIMECLUSTER Wizard for NAS executes failover of the NAS-Cluster. In the following, it explains the method of the tuning of the parameter of PRIMECLUSTER Wizard for NAS.

Turning of the control facility for the NAS-Cluster

1. The GLS resource monitors it between the cluster node and Switching-HUB. It should be set that failover of the NAS-Cluster doesn't execute it until the switching of the NIC of GLS is completed.
   In a word, it is necessary to meet the requirement of following.
   Monitoring Interval of GLS detector (a) + Switching time of the NIC with GLS (b) < Starting time of the NAS-Cluster failover (X)

   (a) + (b) = 10 (sec) + 30(sec) or 60(sec) < X (sec)

   * Switching time of the NIC with GLS

   case1	not monitoring between HUB and HUB	about 30 sec
   case2	monitoring between HUB and HUB	about 60 sec

   
   Refer to "PRIMECLUSTER Global Link Services Installation and Administration guide."

2. After 300(recommended value) seconds pass, the RemoteFileSystems resource to monitor between the cluster node and the NAS device becomes faulted resource if the trouble is detected.
   Therefore, the value in which the failure detection time of NAS-Cluster and the failover time of NAS-Cluster are added should be within at 300 seconds.
   In a word, it becomes like the next expression.

   Starting time of the NAS-Cluster failover (X) < RemoteFileSystems failure time (300 sec) - time of the NAS-Cluster failover

Therefore, it becomes the following.

The NAS cluster control facility will be initiated as follows:

As shown in the above figure, the time required for completing the NAS cluster control facility (1) is (m).

• When executing takeover with the range of (l)
  The NAS cluster control facility will be initiated being unable to access NAS devices because of NIC switching, so this will disable takeover processing.
• When executing takeover with the range of (m)
  RemoteFileSystems resources will time out and enter faulted before the NAS cluster control facility is completed, so this will disable takeover processing.
  

Turning of the PRIMECLUSTER Wizard for NAS Configuration for ping command

Default value is following:

The NAS-Cluster failover beginning time in default can be calculated from the following expression.

The NAS-Cluster failover beginning time in default is 95 sec.

The required time for failover changes by the environment.

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