Free Nutanix NCS-Core Practice Exam with Questions & Answers | Set: 6

In Nutanix, a cluster with RF2 (Redundancy Factor 2) can tolerate the failure of a single node or drive1. However, to ensure that the cluster can survive a complete rack failure without negatively affecting workload performance, we need to consider rack awareness. When rack fault tolerance is enabled, the cluster has rack awareness and the guest VMs can continue to run with failure of one rack (RF2) or two racks (RF3). The redundant copies of guest VM data and metadata exist on other racks when one rack fails2.

Given the current cluster configuration (30 nodes distributed 10 nodes per rack across three 42U racks), adding 3 additional nodes per rack (9 nodes total) would increase the redundancy of the cluster and improve its ability to withstand a complete rack failure. This is because the additional nodes would provide more storage capacity and compute resources, allowing the cluster to continue running workloads even if one rack fails.

References:

• Understanding Fault Domains and Rack Awareness | Nutanix Community
• RF2 -> RF3 | Requirements | Nutanix Community

Ref: https://portal.nutan ix.com/page/documents/details?targetId=Prism-Central-Guide-Prism-v510:mul-security-authentication-pc-t.html

In this scenario, the delay and packet loss during failover when one of the network cables is disconnected can be addressed by enabling "Portfast" on the switch ports connected to the Nutanix nodes. Portfast is a Cisco network switch feature that allows network switches to immediately bring ports into the forwarding state during connectivity changes, bypassing the usual listening and learning states of Spanning Tree Protocol (STP). This significantly reduces the time to re-establish network connectivity, thereby minimizing the packet loss during such failover events. Enabling Portfast is crucial for endpoints like servers where quick recovery from disconnections is necessary.References: Cisco Networking Academy materials on STP and Portfast, Nutanix Bible.

Ref: https://portal.nutanix.com/page/documents/kbs/details?targetId=kA032000000TT8DCAW

Ref:

rx_crc_errors are caused either by faults in layer 1 (in the past, we have seen failed twinax cables and incorrect types of fibre being used), or issues with jumbo frames on the network. In an environment with 10 Gig switches that use cut-through forwarding (Cisco Nexus, Arista, Cisco devices using IOS default to Store and Forward switching), any packets that come into the switch will get forwarded out the destination interface once the switch has read the destination MAC address. If that packet has an MTU over what is configured on the interface, it will cut off the packet at the designated MTU, causing the server to receive a malformed packet, which will throw a CRC error.

If you have a layer 1 issue, you will see rx_crc_errors, not on all but one or two nodes.

For creating a Disaster Recovery Test plan for Nutanix environments, verifying that VMs receive the correct IP address after a failover is critical to validate VM availability across the network. This check is essential to ensure that network configurations and DHCP/Static IP settings are correctly applied post-failover, enabling proper network communications and access to services hosted on the VMs. Ensuring correct IP addressing is fundamental to the successful operation of DR strategies in virtualized environments.References: Nutanix Disaster Recovery Best Practices, Nutanix Network Configuration for DR environments.

https://portal.nutanix.com/page/documents/details?targetId=Web-Console-Guide-Prism-v5_10:wc-protection-domain-failback-disaster.html

The command ncli pd deactivate_and__destroy_vms name=<protection_domain_name> is a critical operation in managing Nutanix environments, particularly in scenarios involving disaster recovery and replication.

• This command deactivates the protection domain and deletes all VMs associated with that protection domain from the source site (Site A in this case). This operation is generally part of a planned migration or failover process where the VMs are intended to be run from the remote site (Site B).
• After this operation, the protection domain at Site A is no longer active, meaning it has been effectively removed along with its associated VMs, thus clearing the way for Site B to take over operations without conflict from the original site.

References:This action and its implications are covered under Nutanix disaster recovery and high availability strategies, detailed in both the Nutanix Bible and official Nutanix NCS-Core training materials, which discuss the management of protection domains and replication processes.

ref http://www.joshodgers.com/tag/cpu-ready/

Erasure coding is a method of data protection in which data is broken into fragments, expanded and encoded with redundant data pieces, and stored across a set of different locations or storage media. The goal of erasure coding is to enable data that becomes corrupted at some point in the disk storage process to be reconstructed by using information about the data that’s stored elsewhere in the array1.

In the context of Nutanix, erasure coding increases the usable capacity on a cluster. Instead of replicating data, erasure coding uses parity information to rebuild data in the event of a disk failure1. The capacity savings of erasure coding is in addition to deduplication and compression savings1.

Given the characteristics of the VM in the question (large/sequential writes, data kept for years, data accessed only at the end of the year), Post-Process Compression would be the most suitable feature to utilize to save space. This is because Post-Process Compression, as the name suggests, compresses data after it has been written to the storage, which is suitable for data that is not accessed frequently2.

References:

• Erasure Coding | Nutanix Community
• Nutanix Support & Insights
• Introducing AOS 6.6: Enhanced data services and simplified … - Nutanix

Nutanix Enablement Starter Packs (ESPs) are resources designed to aid Nutanix partners in ramping up their knowledge and capabilities with Nutanix solutions. These packs typically include training materials, guides, promotional materials, and more. They are most commonly found in the Nutanix Partner Portal, which is designed to support Nutanix partners in their sales and technical education efforts.

References:

• Nutanix Bible: Partner Resources
• Nutanix University: Partner Enablement Programs