- Volume Not On Preferred Path (VNOPP) is a condition that is observed on the storage in the Recovery Guru and in the Major Event Log (
Event Type 4011).
- This condition is reported when a volume, or multiple volumes are owned by their non-preferred controller for a period of time that exceeds the Failover Alert Delay timer (default 5 minutes).
- VNOPP is commonly caused by, but not limited to, any of the following:
- Controller reboot (example: PANIC, manual reset, Ancient IO, WDTO).
- Non-existent connection to a volume's owning controller.
- Misconfigured host mappings.
- Break in connection/instability in the SAN between a Host and the owning controller (example: Bad cable, bad SFP, bad HBA port, switch port bounce).
- Improperly configured SAN Host multipath.
- Unstable or misbehaving array controller.
- This article provides a systematic approach to identify what caused a VNOPP, fix the underlying issue (if necessary), and reassign the volume(s) back to their preferred owner.
Do not upgrade controller firmware to try to fix volumes not on preferred path issue. Upgrading while the system is not stable can result in unpredictable behavior including outages.