NCSE-Core Reviews Questions

For highly active SQL workloads that write I/Os in 2 MB chunks to a vDisk, compression is the most suitable storage optimization technology. Compression works well with larger I/O sizes and can significantly reduce the storage footprint, providing better capacity optimization. This approach ensures that the large chunks of data are compressed efficiently, maximizing storage utilization and performance​​.

When addressing the prospect's need to refresh their environment with a small budget, it is crucial to highlight Nutanix's capabilities that can efficiently utilize their resources and manage their widespread satellite offices. The core data center's low utilization indicates room for improvement in resource management and cost-effectiveness. Here's a detailed explanation of the selected capabilities:

A. Multi-site management:

Nutanix Prism Central allows centralized management of multiple sites, including satellite offices. This capability is essential for managing infrastructure across the prospect's 25 satellite offices efficiently.

Centralized management reduces the complexity and operational overhead associated with maintaining multiple disparate systems. This leads to better resource utilization and easier scalability.

Analyze the CPU utilization data:

Historical CPU utilization data indicates that peak CPU utilization never exceeds 50% on either physical host.

This implies that the existing physical CPUs are underutilized.

Calculate vCPU

ratio:

Given that peak utilization is only 50%, a conservative approach would be to use a lower vCPU to pCore ratio to avoid overcommitment and ensure performance.

Recommended ratio:

A 2:1 vCPU to pCore ratio is appropriate in this scenario to ensure that there is ample CPU capacity and to avoid potential performance bottlenecks.

References:

Nutanix Sizer tool recommendations and best practices for CPU allocation in virtualized environments.

Understanding the Application Requirements:

The application is very transactional with a 28/72 random, read/write ratio. This indicates a high write intensity, which necessitates optimized storage configurations to handle the I/O load efficiently.

Add Multiple Virtual Disks:

Option B: Add a minimum of four virtual disks to each VM and aggregate them on guest OS level:

By adding multiple virtual disks and aggregating them within the guest OS, the I/O operations can be spread across multiple disks. This can significantly improve I/O performance by leveraging parallelism and reducing I/O contention on a single disk.

This approach also helps in better utilizing the underlying storage infrastructure, which can include multiple SSDs and HDDs managed by Nutanix Distributed Storage Fabric (DSF)​​.

Analysis of Other Options:

Option A: Add one large SSD to each node and enable Flash Mode for the VMs:

Adding a single large SSD may not fully leverage the parallel I/O capabilities needed for high transactional workloads.

Option C: Add a minimum of four SSDs to each node to ensure all writes go to the SSDs:

While this improves performance, it focuses on node-level configuration rather than optimizing VM-level disk I/O distribution.

Option D: Add one large virtual disk to each VM and use it for all application data:

This creates a bottleneck as all I/O operations are directed to a single virtual disk, limiting performance improvements.

Conclusion:

For optimal performance of a highly transactional application with a high write ratio, adding multiple virtual disks and aggregating them within the guest OS is the most effective solution.

References: Nutanix best practices for VM and storage configuration.