3V0-23.25 Practice Questions

Dedicated VMFS datastores on assigned Fibre Channel arrays meet both the performance and separation requirements. VCF supports Fibre Channel-backed VMFS as principal storage for workload domains, making it valid as the primary datastore type for the tier-1 business application cluster. Fibre Channel provides low-latency block storage, resilient pathing, SAN zoning, LUN masking, and mature enterprise performance characteristics. Because the existing FC arrays are partitioned by business unit, dedicated datastores preserve organizational separation and avoid mixing business-unit workloads on shared storage resources. The same dedicated FC-backed VMFS approach can also be used as supplemental storage after the workload domain exists, allowing extra capacity or specialized tiers while maintaining separation. Shared VMFS datastores do not satisfy the organizational separation requirement because they allow multiple business units to consume the same datastore boundary. vSAN is explicitly excluded, so the design must rely on supported non-vSAN storage. Automated VM placement can be supported by VMFS datastore clusters and Storage DRS where datastores are compatible and similarly managed. Reference topics: Fibre Channel Storage Model, VMFS Datastores, Principal Storage, Supplemental Storage, Datastore Clusters.

The two major contributors are RAID overhead and Operational Reserve. With the default policy set to FTT=1 using RAID-1 mirroring, vSAN stores two copies of protected data. The capacity planning guidance states that when Failures to tolerate is set to 1 failure with RAID-1 mirroring, virtual machines can use about 50 percent of raw capacity because each object consumes mirrored space. This is the largest capacity-impacting factor. The second contributor is Operational Reserve, which reserves capacity for vSAN internal operations such as policy changes, rebalancing, object movement, and other transient storage activities. Even when Host Rebuild Reserve is not activated, vSAN capacity monitoring still accounts for the operations threshold/reserve needed to keep the cluster functional during internal activity. Encryption overhead is typically not the primary reason for a 20% capacity difference. Host upgrade overhead is not a vSAN capacity category. VM swap can consume capacity, but it does not normally account for most unavailable raw capacity compared with RAID mirroring and operational reservation. Reference topics: vSAN Capacity Planning, RAID-1 FTT=1 Capacity Impact, Operations Reserve, Reserved Capacity.

When vertically scaling a vSAN ESA cluster, adding the same model and capacity drives helps preserve a balanced and predictable cluster design. vSAN works best when hosts use uniform storage configurations. The guidance states that unbalanced host configurations reduce predictability of storage performance because vSAN does not store the same number of components on each host, can introduce different maintenance procedures, and can reduce performance on hosts with smaller or different device types. In ESA, each storage device contributes both capacity and performance through the storage pool model, so mixing device models, endurance classes, or capacities can create uneven consumption and inconsistent backend behavior. Using the same drive model and capacity across hosts improves capacity symmetry, keeps maintenance and replacement procedures consistent, and makes performance planning more predictable. The cache-drive option is incorrect because ESA is single-tier and does not use separate cache and capacity tiers. Equal cache and capacity tiers apply to OSA-style thinking, not ES

A.  

The cluster must not include hosts from different subnets or networks (L3).

The default management vSphere cluster must already be stretched.

The cluster must not include DPU-backed hosts.

The cluster must not share a vSAN Storage Policy with any other cluster.

To stretch a vSAN cluster in a VCF Workload Domain, the environment must satisfy specific VCF stretch prerequisites and avoid unsupported configurations. The default management vSphere cluster must already be stretched so the management plane remains available if an availability zone fails. The workload cluster must not include hosts from different subnets or Layer 3 networks because the stretch workflow expects supported site and network placement assumptions for the cluster being stretched. The cluster must also not include DPU-backed hosts, because clusters with DPU-backed hosts are excluded from this stretch operation. In addition, the cluster must not share a vSAN Storage Policy with any other cluster, because shared policies can create policy scope and compliance conflicts during stretch configuration. SSH does not need to be manually activated on all hosts as a prerequisite. The default management cluster being “not stretched” is the opposite of the required condition. Host self-signed certificates are not the listed blocking condition for this workflow. Reference topics: Stretch vSAN Cluster in VCF, Workload Domain Stretch Prerequisites, vSAN Storage Policy Constraints, Unsupported Stretch Configurations.

vSAN Stretched Clusters meet the availability-zone requirement by extending a single logical vSAN cluster across two availability zones and using a witness for quorum. This provides rapid recovery from a site or availability-zone failure because workloads remain protected by the stretched topology and vSAN site-failure tolerance. vSAN Storage Cluster addresses the need for scalable, high-performance storage that can grow independently as application capacity requirements increase. In VCF 9.0, a vSAN Storage Cluster is based on vSAN ESA and provides disaggregated storage to vSAN compute or HCI clusters. This design supports storage-dense NVMe-based nodes, high IOPS, low latency, independent capacity scaling, and centralized storage services. Encryption at rest and in transit are native vSAN capabilities that can be enabled on the vSAN-backed storage architecture. vSAN File Service is for file shares, and vSAN iSCSI Target Service is for presenting block LUNs to external initiators; neither is required by the stated application-storage design. vSAN Data Protection is valuable for snapshots and recovery points, but the core architecture requirements are best satisfied by stretched site resilience plus scalable vSAN storage clustering. Reference topics: vSAN Storage Cluster, vSAN Stretched Cluster, vSAN ESA, vSAN Encryption.