NS0-593 Exam Dumps : NetApp Certified Support Engineer ONTAP Specialist

The maxdirsize is the maximum size of a directory in a FlexVol or FlexGroup volume. It is determined by the number of inodes allocated to the directory. If the directory contains more files than the maxdirsize can accommodate, then the ONTAP software will return an out of space error message to the host, even if the volume has enough free space. This can happen when a FlexGroup volume has a flat directory structure with millions of files, as the maxdirsize is not automatically adjusted for FlexGroup volumes12. References: 1: FlexGroup volumes: Frequentlyasked questions | NetApp Documentation 2: How to increase the maxdirsize of a FlexVol volume - NetApp Knowledge Base

 The mgwd user space process is responsible for managing the cluster configuration and providing the management interface for ONTAP. If this process crashes, it may generate a core dump file in the /mroot/etc/mgwd/core directory of the node. To access this directory, you need to log in to the systemshell, which is a Linux shell that runs on the node. The systemshell can be accessed by logging in to the nodeshell using the node console and then running the systemshell command. The nodeshell is a custom shell that provides access to ONTAP commands and utilities. The service processor and the clustershell are not relevant for collecting core dumps from the mgwd process. References = ONTAP 9 Cluster Administration, page 29-30; ONTAP 9 Troubleshooting Guide, page 23-24.

• A speed mismatch occurs when the cluster ports on different nodes have different speeds, such as 10 Gbps and 40 Gbps1.
• A speed mismatch can cause packet loss, retransmits, and latency on the cluster network, especially when data is accessed indirectly, meaning that the node serving the data is different from the node hosting the LIF2.
• In this scenario, the AFF A300 nodes have 10 Gbps cluster ports, while the AFF A700 nodes have 40 Gbps cluster ports, creating a speed mismatch on the cluster interconnect34.
• The Cisco Nexus 3132Q cluster interconnect switches support both 10 Gbps and 40 Gbps cluster ports, but they have a shallow buffer size of 9 MB per port, which can be easily overwhelmed by the bursty traffic generated by the speed mismatch.
• To solve this problem, you need to either upgrade the cluster ports on the AFF A300 nodes to 40 Gbps, or downgrade the cluster ports on the AFF A700 nodes to 10 Gbps, to achieve a homogeneous cluster interconnect1.
• Alternatively, you can use QoS policies to limit the bandwidth of the cluster ports to avoid oversubscription and congestion on the cluster interconnect. References:
• 1: Cluster network cabling, ONTAP 9 Documentation Center
• 2: Cluster Network Latency - Troubleshooting Guide, NetApp Knowledge Base
• 3: AFF A300 Tech Specs, NetApp
• 4: AFF A700 Tech Specs, NetApp
• [5]: Why do network speed mismatches create problems with shallow buffered switches?, NetApp Knowledge Base
• [6]: How to use QoS to limit the bandwidth of cluster ports, NetApp Knowledge Base