MPIO and ALUA are the required host/target features to ensure storage failover works correctly for FCP and iSCSI clients. MPIO on the host provides multiple available paths to the LUN, allowing I/O to continue when one path or controller is unavailable. ALUA on the target communicates path states to the host so that optimized paths are preferred and non-optimized paths are used correctly during failover. LACP is a link aggregation mechanism for Ethernet networking and does not solve block SAN path selection for FCP; it is also not relevant to FC. SCSI is the command protocol foundation for FCP and iSCSI, but it is not a failover feature by itself. The support engineer must validate the complete SAN failover stack: host multipathing software, correct DSM/device handler, ONTAP ALUA reporting, igroup configuration, and redundant LIF/target paths. References/topics: ONTAP SAN failover, MPIO, ALUA, FCP/iSCSI host access, and TR-4080 SAN best practices.

VLANs are used in ONTAP environments to create logical network segmentation, normally by function, tenant, or protocol. Isolating management traffic from data traffic is a valid design reason because management interfaces should remain on a protected administrative network, separate from NAS or SAN client paths. Isolating iSCSI traffic from NAS traffic is also valid because iSCSI carries block storage traffic and is commonly placed on dedicated networks or VLANs for predictable latency, security, and failure-domain control. VLANs do not isolate UDP from TCP; those are transport protocols and are handled by IP stack behavior, firewalling, or application design rather than VLAN design. FC is not ordinary IP traffic, so isolating FC from other IP traffic is not a correct VLAN use case for ONTAP Ethernet networking. The support decision is to select segmentation examples that match ONTAP IP networking. References/topics: ONTAP VLANs, broadcast domains, management network isolation, iSCSI network separation, and NAS/SAN traffic design.

Active IQ Cluster Viewer details can be downloaded in PDF, CSV, and XLS formats. These formats support the common operational needs of support and account teams: PDF for fixed presentation and case documentation, CSV for raw data extraction and analysis, and XLS for spreadsheet-based review or customer reporting. DOC is not a standard export format for structured cluster inventory or health data, and HTML is a display format rather than one of the listed downloadable detail formats in this context. Active IQ is used to analyze AutoSupport telemetry, identify risks, display system health, and provide support-relevant inventory and recommendations. Export formats matter because engineers frequently attach evidence to cases, share inventory with customers, or perform offline review. The correct selections are the formats that preserve report data in portable or analyzable files. References/topics: Active IQ Cluster Viewer, report export, PDF/CSV/XLS downloads, AutoSupport telemetry review, and support documentation.

A disk/shelf count mismatch AutoSupport message indicates that nodes in the cluster do not agree about visible disks or shelves, so the first areas to inspect are drive paths and SAS cabling. Drive paths reveal whether each controller can see the expected disks through the expected redundant routes. SAS cabling is a common physical cause because a missing, crossed, loose, or failed cable can make one path or shelf segment disappear from one controller's view. IOM firmware and drive firmware can matter in broader shelf troubleshooting, but a count mismatch is primarily about visibility and pathing, not code level on a disk or module. The support engineer should validate multipath HA, shelf stack cabling, port connections, and path status before replacing hardware. Correct path redundancy is essential because ONTAP expects consistent shelf and disk inventory across the HA pair or cluster. References/topics: AutoSupport disk/shelf count mismatch, SAS cabling, drive path validation, multipath HA, and shelf visibility troubleshooting.