Dear everyone,
When performing an ONTAP upgrade on NetApp systems, we observe an I/O interruption lasting approximately 10 to 30 seconds, which causes all applications to terminate.
This interruption occurs frequently during the upgrade process, and we are looking for ways to minimize its impact.
We have tested the following upgrade approaches:
1. Manual takeover using the storage failover takeover command
2. Step-by-step takeover (LIF migration → CFO takeover → SFO takeover)
3. ANDU (Automated Non-Disruptive Upgrade)
We confirmed that I/O interruption occurs with all of the above methods.
Among them, option 2 (step-by-step takeover) results in the least impact, but the interruption is still noticeable.
This issue does not appear to be related to system utilization, and we have observed that it occurs more frequently on ONTAP 9.12.1 and later versions, even when running the latest patch releases.
We would appreciate your advice on:
Whether this behavior is expected in recent ONTAP versions
Any known issues or changes in takeover/upgrade behavior since 9.12.1
Best practices or configuration recommendations to further reduce or eliminate this I/O interruption during upgrades.
Thank you.
