PASSEDinfrastructure / iscsi_target_unreachable

iSCSI Target Unreachable — Multipath Failover

An iSCSI storage target becomes unreachable on the primary path after a switch failure. Multipath failover engages but the secondary path is congested, causing severe performance degradation for all connected initiators.

Pattern

CONNECTION_REFUSED

Severity

CRITICAL

Confidence

85%

Remediation

Remote Hands

Test Results

Metric	Expected	Actual
Pattern Recognition	CONNECTION_REFUSED	CONNECTION_REFUSED
Severity Assessment	CRITICAL	CRITICAL
Incident Correlation	Yes	12 linked
Cascade Escalation	N/A	No
Remediation	—	Remote Hands — Corax contacts on-site support via call, email, or API

Scenario Conditions

iSCSI storage array with dual-path connectivity. Primary switch (iscsi-sw1) port failure. Multipath failover to secondary path via iscsi-sw2. Secondary path at 85% bandwidth utilization. 8 ESXi hosts connected as initiators.

Injected Error Messages (2)

iSCSI target unreachable on primary path — connection refused on 10.10.7.50:3260 via primary network, switch iscsi-sw1 port Gi0/12 down, multipath failover engaged to secondary path, connection refused on all primary path sessions, 8 initiators failed over

ESXi hosts reporting degraded storage performance — iSCSI multipath running on single path after primary connection refused, secondary path congested at 85% bandwidth, datastore latency increased from 2ms to 45ms, connection refused on primary iSCSI portal

Neural Engine Root Cause Analysis

The iSCSI storage target at 10.10.7.50:3260 is experiencing a critical infrastructure failure. The primary root cause appears to be a physical network switch failure where switch iscsi-sw1 port Gi0/12 is down, causing connection refusal on the primary path. This has triggered multipath failover to secondary paths, but all primary path sessions are failing, affecting 8 initiators and potentially causing storage I/O disruptions across dependent systems.

Remediation Plan

1. Immediately verify secondary path stability and performance to ensure continued storage access. 2. Check physical connectivity and status of switch iscsi-sw1 port Gi0/12 - inspect cables, port LEDs, and switch logs. 3. If port is administratively down, bring it up; if hardware failure, replace cable or use alternate port. 4. Once primary path connectivity is restored, verify all 8 initiators can reconnect to primary path. 5. Monitor multipath status and performance metrics to ensure full recovery. 6. Review switch maintenance schedules and implement redundancy improvements to prevent future single points of failure.

Tested: 2026-03-30Monitors: 2 | Incidents: 2Test ID: cmnck06x305zwobqea2z0swn0