Unveiling NetApp's Recommended CPU/Disk Utilization for Flawless ONTAP Upgrades

When planning an upgrade for your NetApp ONTAP system, ensuring that CPU and disk utilization levels are within recommended parameters is crucial for a smooth and successful process. This helps prevent performance degradation, unexpected disruptions, or potential upgrade failures. Based on NetApp's official documentation and guidelines, particularly in the context of the NS0-093 exam, specific thresholds are advised.

Key Highlights: Understanding Utilization Thresholds

General Planning Guideline (NS0-093 Context): For overall upgrade planning and system readiness, the widely cited recommendation is to ensure both disk and CPU utilization are less than 70%. This provides a safe operational margin.
Specific Pre-Upgrade Monitoring: NetApp Knowledge Base articles detail a more stringent guideline for active pre-upgrade checks, recommending that CPU and disk utilization should ideally be less than 50% during specific monitoring periods.
Tool-Assisted Verification: Employing tools like NetApp Upgrade Advisor and CLI commands such as sysstat is essential for accurately assessing current utilization levels and planning accordingly.

The Recommended Utilization: A Dual Perspective

Addressing your specific question regarding the recommended value for disk and CPU utilization when planning an ONTAP upgrade, with the provided options:

The most appropriate answer, especially considering the NS0-093 exam context and general planning guidelines, is:

D. less than 70%

This threshold is often emphasized as a general best practice to ensure the system has adequate resources to handle the upgrade process without impacting ongoing operations significantly.

The <70% Guideline: A Prudent Planning Benchmark

Why <70%?

Maintaining CPU and disk utilization below 70% before initiating an ONTAP upgrade serves as a crucial precautionary measure. This threshold ensures that there's sufficient available capacity to accommodate the additional load imposed by the upgrade processes. Upgrade activities can include data migration, controller takeovers and givebacks (in HA configurations), and various system checks, all of which consume system resources. Exceeding this utilization level could strain the system, potentially leading to:

Increased latency for applications and users.
Extended upgrade durations.
In worst-case scenarios, upgrade failures or data service disruptions.

This guideline is frequently referenced in preparation materials for certifications like the NetApp Accredited Hardware Support Engineer (NS0-093), underscoring its importance in professional practice.

The <50% Guideline: A Stricter Check for Imminent Upgrades

Detailed Monitoring for Optimal Conditions

While <70% is a sound general planning figure, NetApp's official Knowledge Base articles provide a more granular recommendation for the period immediately preceding an upgrade. Specifically, documentation suggests that during active monitoring (e.g., observing system statistics for a period like 30 seconds using tools like sysstat), CPU and disk utilization values should ideally not exceed 50%. For instance, one recommendation mentions that "The values in the CPU and Disk Util columns should not exceed 50% for all 10 measurements reported" during such checks.

This stricter <50% threshold for active pre-upgrade measurements ensures the system is under a light load, minimizing any potential interference with the delicate upgrade operations. Adhering to this provides an even greater safety margin.

NetApp Data ONTAP CPU Load Monitoring Example

Example of CPU load monitoring, a key aspect of pre-upgrade checks.

Reconciling the Thresholds

The <70% threshold can be seen as the broader "safe zone" for planning and general system health leading up to an upgrade. The <50% threshold is a more specific, ideal target for the system's state during the actual pre-upgrade validation and immediate execution window. If utilization consistently hovers between 50% and 70%, it warrants closer investigation and potential workload adjustments before proceeding with the upgrade.

Essential Tools for Upgrade Planning and Monitoring

NetApp provides robust tools to assist administrators in planning and executing ONTAP upgrades smoothly, including the critical task of assessing system utilization.

NetApp Upgrade Advisor

Upgrade Advisor, available through Active IQ Digital Advisor, is a powerful tool designed to simplify and de-risk the ONTAP upgrade process. It provides tailored intelligence and guidance by:

Analyzing your specific cluster configuration and AutoSupport data.
Identifying potential risks, prerequisite tasks, and any pre-upgrade actions needed, including checks for system utilization.
Generating a customized, step-by-step upgrade plan.
Highlighting known issues or blockers that could affect the upgrade.

Using Upgrade Advisor is highly recommended as it incorporates these utilization best practices into its assessment, helping to ensure your system is truly ready for the upgrade.

Command-Line Interface (CLI) Monitoring

For direct, real-time monitoring of system performance metrics, the ONTAP CLI offers commands like sysstat. For example, running sysstat -M 1 can provide per-second updates on CPU utilization across different processors (Network, Exempt, WAFL, RAID), as well as disk and network statistics.

Example output snippet (conceptual):


CPU   Nwk_Excl  Nwk_Lg   Nwk_Exmpt  RAID   WAFL_Excl WAFL_Del  WAFL_XClean SM_Exempt Exempt  Disk Util
10%   0%        1%       1%         2%     2%        1%        1%          1%        1%      35%

This allows administrators to perform the detailed monitoring recommended (e.g., checking that utilization remains below 50% over several measurements) just before starting the upgrade procedure.

Visualizing System Readiness for ONTAP Upgrade

To better understand the multifaceted nature of upgrade readiness, the following chart illustrates key factors, including CPU and disk utilization. It compares an "Optimal State" for proceeding with an upgrade, an "Acceptable State" where caution and close monitoring are advised, and a "Cautionary State" where addressing issues is recommended before upgrading. Utilization figures are represented as percentages (lower is better), while other factors like memory and network capacity are scored (higher is better), and completion statuses are represented on a 0-100 scale.

This chart emphasizes that while CPU and disk utilization are critical, they are part of a broader spectrum of considerations for a successful ONTAP upgrade. An optimal state shows low utilization and high readiness in other areas.

NetApp ONTAP Upgrade: Pre-Upgrade Tasks Overview

For a practical walkthrough of the pre-upgrade tasks involved in a NetApp ONTAP upgrade, including system checks, the following video provides valuable insights. It covers many of the considerations discussed, emphasizing the importance of thorough preparation.

NetApp ONTAP 9 Upgrades Part 1: Pre-Upgrade Tasks. This video outlines crucial steps before an upgrade.

Watching such resources can complement official documentation by providing visual demonstrations and practical tips from experienced professionals, reinforcing the importance of steps like checking system health and utilization.

Comparative Summary: Utilization Thresholds

The following table summarizes the different utilization thresholds discussed and their primary contexts when planning and executing an ONTAP upgrade:

Threshold	Context	Primary Purpose	Source Emphasis
Less than 50%	Active pre-upgrade monitoring (e.g., via `sysstat` over specific short intervals)	Ensure system is under light load immediately before starting upgrade processes; minimize interference.	NetApp Knowledge Base articles detailing specific pre-upgrade check procedures.
Less than 70%	General upgrade planning; overall system readiness assessment.	Provide a safe operational margin for system resources during the entire upgrade window; general system health.	NS0-093 exam preparation materials; broader best practice guidelines for system stability.

Both thresholds are important. The <70% mark serves as a good general indicator for planning, while striving for <50% during the immediate pre-upgrade checks offers a higher degree of confidence for a smooth operation.

Mindmap: Key Facets of ONTAP Upgrade Planning

Successful ONTAP upgrade planning involves multiple interconnected considerations. This mindmap provides a visual overview of these critical components, where CPU and disk utilization assessment forms a key part of the pre-upgrade checks.

mindmap root["ONTAP Upgrade Planning"] id1["Pre-Upgrade Assessment"] id1a["System Health Checks"] id1b["CPU & Disk Utilization
(<70% general, <50% active check)"] id1c["Interoperability Verification
(HBA, Firmware, Software)"] id1d["Backup & Recovery Plan"] id1e["Review Release Notes"] id2["Tools & Resources"] id2a["NetApp Upgrade Advisor"] id2b["Active IQ Digital Advisor"] id2c["`sysstat` & other CLI tools"] id2d["NetApp Documentation & KBs"] id2e["Interoperability Matrix Tool (IMT)"] id3["Execution Strategy"] id3a["Automated Nondisruptive Upgrade (ANDU)"] id3b["Manual Nondisruptive Upgrade (CLI/System Manager)"] id3c["Maintenance Window Planning"] id3d["Rollback Plan"] id4["Post-Upgrade Procedures"] id4a["System Health Verification"] id4b["Performance Monitoring"] id4c["Application Testing"] id4d["Documentation Update"]

This mindmap highlights that checking CPU and disk utilization is an integral step within a broader framework of preparatory actions, all aimed at ensuring a successful and non-disruptive upgrade.