Netapp NetApp Certified Support Engineer ONTAP Specialist NS0-593 Question # 10 Topic 2 Discussion

A type B consistency point (CP) is triggered when the NVRAM buffer is full and needs to be flushed to disk. A type B CP indicates that the write workload is higher than the disk throughput, and the system is experiencing back pressure1

A switchless cluster is a cluster configuration that does not use external switches for cluster interconnect and management network. A switchless cluster has lower bandwidth and redundancy than a switched cluster, and is limited to two nodes2

The exhibit shows the output of the sysstat -x command, which displays the system performance statistics in extended mode. The output shows that the system has high CPU utilization, high disk utilization, high NVRAM utilization, and several type B CPs. These are signs of performance issues and resource contention3

The best corrective action to address these consistency points is to add an additional shelf of twenty-four 1.8 TB disks. This will increase the disk capacity and throughput, and reduce the disk utilization and the frequency of type B CPs4

Creating additional data LIFs will not address the consistency points, because the data LIFs are used for data access protocols, not for NVRAM flushing5

Converting the 2-node switchless cluster to a 2-node switched cluster will not address the consistency points, because the cluster interconnect and management network are not related to the disk performance6

Replacing the twenty-four 1.8 TB disks with twelve 4 TB disks will not address the consistency points, because the disk throughput will not increase, and the disk utilization will remain high7

References:

1: Where can I learn more about Consistency Points? - NetApp Knowledge Base 2: ONTAP 9 - Cluster and SVM Peering Express Guide - The Open Group 3: ONTAP 9 - Commands: Manual Page Reference - The Open Group 4: ONTAP 9 - Hardware Universe - The Open Group 5: ONTAP 9 - Network Management Guide - The Open Group 6: ONTAP 9 - Clustered Data ONTAP Concepts Guide - The Open Group 7: ONTAP 9 - Logical Storage Management Guide - The Open Group