Netapp NS0-593 NetApp Certified Support Engineer ONTAP Specialist Exam Practice Test

= The FIFO message before NMI is useful for investigating the issue because it shows the state of the system before the non-maskable interrupt (NMI) was triggered by the L2 watchdog timeout. The FIFO message contains information about the CPU registers, the stack pointer, the instruction pointer, and the last executed instructions. This can help identify the cause of the system hang or deadlock that led to the watchdog reset. The other FIFO messages are not useful because they show the state of the system after the reset or shutdown, which may not reflect the original problem. References = https://kb.netapp.com/onprem/ontap/hardware/Handling_L2_Watchdog_Resets_on_the_FAS8200_and_AFF_A300_platforms

https://docs.netapp.com/us-en/ontap-metrocluster/install-ip/task_sw_config_restore_defaults.html

= A user quota is a limit on the amount of disk space or the number of files that a user can consume on a volume. A user can be represented by multiple IDs, such as UNIX user ID (UID), Windows user ID (SID), or name mapping ID. A file owned by any of these IDs is subject to the restriction of the user quota. If a user has files in different directories or qtrees within the same volume, all of those files count towards the user’s quota limit. Therefore, if other files within the volume are also owned by the user, they could exceed the user quota and prevent the user from saving more files to their home drive, even if the home drive itself shows minimal data usage. References = How quotas work with users and groups overview, ONTAP - How quotas work with users and groups

• IQN stands for iSCSI Qualified Name, which is a unique identifier for an iSCSI initiator or target1.
• ONTAP uses IQN to authenticate and authorize iSCSI sessions2.
• If two hosts have the same IQN, they will cause a conflict and ONTAP will reject the new session request from the second host3.
• This will result in the host losing the connection to the iSCSI target and then reporting that the session was reestablished, as shown in the exhibit.
• To avoid this problem, each host should have a unique IQN. References:
• iSCSI Qualified Name (IQN) - NetApp
• iSCSI authentication and authorization - NetApp
• Troubleshooting iSCSI issues - NetApp
• [Configuring iSCSI initiators - NetApp]

 = The correct action to bring the cluster online and allow Node02 to serve data is to perform a takeover with the storage failover takeover -ofnode Node01 -option force command. This command will force Node02 to take over the resources of Node01 and serve the data from both nodes. This is necessary because Node01 is not responding and cannot initiate a graceful takeover. The other options are not correct because they will either destroy the existing cluster configuration (A and D) or reboot the node without taking over the resources of the other node(B). References = 1 Halt or reboot a node without initiating takeover in a two-node cluster - NetApp Documentation 2 Solved: Graceful shut down - NetApp Community

= CPU utilization in ONTAP is not a linear measure of the system load, nor can it be used alone as a measure of the overall system utilization. ONTAP uses a Coarse Symmetric Multiprocessing (CSMP) design which partitions system functions into logical processing domains, each with its own scheduling rules and resource availability. Therefore, a high CPU utilization does not necessarily indicate a performance problem, unless it is accompanied by other contributing factors such as high latency, low throughput, or high queue depth. ONTAP has several mechanisms to optimize CPU usage and balance the workload across the cores, such as WAFL parallelization, exempt processing, and CPU pinning. The CPU utilization reported by the sysstat command is an average across all cores and domains, and does not reflect the actual CPU activity or availability for each domain. Therefore, the CPU is not a first-order monitoring metric for ONTAP, and other metrics such as latency, throughput, and queue depth should be considered first. References = What is CPU utilization in Data ONTAP: Scheduling and Monitoring?, How to measure CPU utilization, What are CPU as a compute resource and the CPU domains in ONTAP 9?, Monitoring CPU utilization before ONTAP upgrade

The error message indicates that the access is denied for user ‘anonymous user’ (Vserver 50), from client IP 10.10.10.10 accessing resource ‘/offload-target’. This means that the application is not providing a valid user name or access key to authenticate with the ONTAP S3 server. According to the NetApp documentation1, ONTAP S3 server supports both v2 and v4 signatures, but v2 signatures are deprecated and not recommended. Therefore, the application should use v4 signatures to access the ONTAP S3 bucket. Additionally, the application should specify the bucket name in the host name, not in the resource path, as shown in the following example2:

https://bucket-name.s3-server-name.com/object-name

References = 1 ONTAP S3 Server Overview - NetApp Documentation 2 Accessing an ONTAP S3 bucket - NetApp Documentation

• Having an Essentials package enables you to convert to another licensing option. This is true because the Essentials package is a capacity-based licensing option that allows you to pay for Cloud Volumes ONTAP per TiB of capacity. You can switch to another capacity-based package or to a Keystone Flex Subscription at any time1.
• BYOL licenses are purchased directly from NetApp. This is true because BYOL stands for Bring Your Own License, which means you need to obtain a license from NetApp before deploying Cloud Volumes ONTAP systems in any cloud provider2.
• Capacity-based license packages support only single-node configurations. This is false because capacity-based license packages support both single-node and HA configurations1.
• AWS Marketplace contracts cannot be mixed with BYOL. This is false because you can mix AWS Marketplace contracts with BYOL as long as the license type matches the instance type3. References: 1: Cloud Volumes ONTAP licensing | NetApp Documentation 2: Set up licensing for Cloud Volumes ONTAP in Google Cloud - NetApp 3: Set up licensing for Cloud Volumes ONTAP in AWS - NetApp

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 panic message indicates that the node encountered a fatal error while accessing the PCI card in slot 31. This could be due to a hardware failure, a firmware issue, or a driver problem. The first component to troubleshoot is the PCI card in slot 3, as it is the most likely source of the error. You can use the system node hardware pci show command to check the status of the PCI card and the system node hardware firmware update command to update the firmware if needed2. You can also use the Panic Message Analyzer tool from the NetApp Support Site to determine whether your panic was caused by a known software issue3. References = 1: REBOOT (panic) ALERT - AutoSupport message 2: [system node hardware pci show] 3: [Panic Message Analyzer tool]

The VMware feature that is supported by ONTAP software to identify and follow I/Os from each VM on the shared FC LUN-backed datastores is Virtual machine ID (VMID). VMID is a unique identifier assigned to each VM by the vCenter Server. ONTAP software can use VMID to map the VMs to the FC LUNs and provide visibility into the I/O performance and latency of each VM. This feature is also known as Virtual Storage Console (VSC) for VMware vSphere12. References: 1:Virtual Storage Console for VMware vSphere | NetApp Documentation 2: How to use Virtual Storage Console (VSC) to monitor the performance of virtual machines - NetApp Knowledge Base

= AutoSupport is enabled by default for Cloud Manager and ONTAP Cloud systems. It proactively monitors the health of your systems and sends messages to NetApp technical support. To enable AutoSupport, you must provide your NetApp Support site credentials to Cloud Manager. If your credentials are incorrect or expired, Cloud Manager will not be able to send AutoSupport messages to NetApp. Therefore, the solution for this issue is to verify that your NetApp Support site credentials are correctly added to Cloud Manager. References = Troubleshooting Cloud Manager and ONTAP Cloud, Set up AutoSupport

The error message indicates that the specified path “/vol1” does not exist in the namespace belonging to Vserver “svm1”. This means that the volume “vol1” has not been mounted to the Vserver’s namespace, which is required for creating a share. The volume type, the CIFS service status, and the CIFS service mode are not relevant to the error. References = https://www.netapp.com/support-and-training/netapp-learning-services/certifications/support-engineer/

https://mysupport.netapp.com/site/docs-and-kb

 The iSCSI service must be enabled on the network interfaces that are used for iSCSI communication. If the iSCSI service is disabled on an interface, the incoming connection requests from the iSCSI initiator will be discarded and the event log will show the message “ISCSI: network interface identifier disabled for use; incoming connection discarded”. To enable the iSCSI service on an interface, you can use the System Manager or the CLI command network interface modify -vserver vserver_name -lif lif_name -data-protocol iscsi. References = Configure the iSCSI protocol with System Manager, [ONTAP 9 Network Management Guide]

• SnapMirror is a data replication technology that allows efficient and flexible data protection and disaster recovery for NetApp ONTAP storage systems1
• SnapMirror transfers data between source and destination volumes using a network connection. SnapMirror can use storage efficiency features such as compression and deduplication to reduce the amount of data transferred and stored1
• SnapMirror transfers are scheduled and controlled by policies that define the frequency, retention, and priority of the transfers. SnapMirror policies can also specify the network bandwidth limit for the transfers2
• SnapMirror transfers are considered background tasks that run in the absence of user workload. SnapMirror transfers can consume CPU and disk resources on both source and destination systems, depending on the amount and type of data being replicated3
• SnapMirror transfers can throttle up or down depending on the availability of system resources and network bandwidth. SnapMirror transfers will throttle up when there is nouser workload, and throttle down when there is user workload. This is to ensure that SnapMirror transfers do not impact the performance of user operations3
• Therefore, if a customer is concerned with high CPU and disk utilization on their SnapMirror destination system, the best answer is to explain that background tasks such as SnapMirror throttle up in the absence of user workload. This is normal and expected behavior, and it does not indicate a problem with the system3

References:

1: ONTAP 9 Data Protection - SnapMirror - The Open Group 2: ONTAP 9 Data Protection - SnapMirror Policies - The Open Group 3: SnapMirror storage efficiency configurations and behavior - Resolution Guide - NetApp Knowledge Base

 The two throughput elements that are controlled by host applications are operation size and concurrency. Operation size refers to the amount of data that is transferred in a single I/O request, and concurrency refers to the number of I/O requests that are issued simultaneously. Both of these factors affect the throughput of a host application, as they determine how much data can be sent or received within a given time period. Larger operation sizes and higher concurrency can increase the throughput, but they may also increase the latency and resource consumption12. References: 1: NetApp Performance Analysis on Data ONTAP - Chapter 3: Host-Side Performance 2: NetApp Performance Analysis on Data ONTAP - Chapter 4: Storage System Performance

FabricPool is an ONTAP feature that enables tiering of cold data from SSD aggregates to low-cost object storage, either on-premises or in the cloud1. FabricPool requires a license to be installed on the cluster, and the license type depends on the cloud tier being used2. In this scenario, the cloud tier is another ONTAP cluster (FAS8300), which is not supported by the new Cloud Tiering license that is used for most FabricPool configurations3. Therefore, the old FabricPool license that is retained for dark sites or MetroCluster systems using FabricPool Mirror must be used3. The FabricPool license defines the amount of capacity that can be tiered to the cloud tier, and it can be increased by add-on orders4. References:

• 1: FabricPool overview5
• 2: FabricPool requirements6
• 3: Install a FabricPool license2
• 4: ONTAP FabricPool (FP) Licensing Overview1

• The error message indicates that the ONTAP Select Deploy VM cannot connect to the vCenter server due to a network issue1.
• One possible cause of this issue is that the IP address of the ONTAP Select Deploy VM is conflicting with another device on the same network2.
• To correct this problem, you need to change the IP address of the ONTAP Select Deploy VM to a unique and valid address that can reach the vCenter server2.
• You can change the IP address of the ONTAP Select Deploy VM by using the Deploy web interface or the Deploy CLI2.
• After changing the IP address, you need to restart the Deploy services and re-add the vCenter server to the inventory2. References:
• 1: Credential authentication failed with: HostConnectionFailed, NetApp Knowledge Base
• 2: Changing the IP address of the Deploy VM, ONTAP Select 9 Documentation Center

• The mailbox disks are the first two disks of the root aggregate on each node of an HA pair. They store the HA state information and the panic dump files. The mailbox disks are used for communication between the HA partners and for takeover and giveback operations1
• The mailbox destroy local command is used to destroy the mailbox disks on the local node. This command is only available in maintenance mode and should be used with extreme caution. The command is intended for situations where the mailbox disks are corrupted or inaccessible and need to be recreated2
• If the mailbox destroy local command is executed on a node that is in takeover mode, the node will panic with the message “Permanent errors on all HA mailbox disks”. This is because the node will lose the HA state information and the panic dump files of the partner node, and will not be able to communicate with the partner node or perform a giveback operation3
• Therefore, if the motherboard of Node-01 is being replaced, and a takeover was initiated from Node-02, and Node-02 panics showing the string “Permanent errors on all HA mailbox disks”, the most likely cause is that the mailbox destroy local command was executed on Node-02 while in maintenance mode. This is a serious error that can result in data loss and system downtime4

References:

1: ONTAP 9 - High-Availability Configuration Guide - The Open Group 2: ONTAP 9 - Commands: Manual Page Reference - The Open Group 3: How to troubleshoot a “Permanent errors on all HA mailbox disks” panic - NetApp Knowledge Base 4: One node PANIC : Permanent errors on all HA mailbox disks - NetApp Knowledge Base