Issue

Use this article to troubleshoot VM startup failure and unsynchronized management-node time.

Environment

• Product: ZCF
• Component: Cloud
• Affected object: VM/DHCP
• Versions: 4.x, 5.x
• Scenario: Startup failure or unsynchronized management-node time

Symptoms

• Startup stalls at the DHCP/userdata stage, network preparation times out, or VM network initialization fails.

Possible causes

• Management-node time is unsynchronized, or the DHCP namespace, dnsmasq, Layer 3 network, or physical-network path is abnormal.

Resolution

1. Confirm time synchronization on management nodes, physical hosts, and storage nodes.
2. Check the DHCP namespace, dnsmasq, Layer 3 network, and related logs.
3. Search for preparation-stage errors by VM UUID and Layer 3 UUID.

Key command

date
ip netns list
ps aux | grep dnsmasq
grep -a -nE "dhcp|prepare|dnsmasq|userdata" /usr/local/zstack/apache-tomcat/logs/management-server.log* /var/log/zstack/zstack-kvmagent.log* 2>/dev/null

Remediation

• Based on the troubleshooting result, repair the affected component, configuration, data state, or connection path.
• If databases, underlying storage, snapshot chains, VM disks, GPU passthrough, or management-service restarts are involved, first confirm backups, scope of impact, and rollback paths.

Verification

• Confirm that the symptom described in this article no longer occurs.
• UI, API, management-node logs, and underlying command output corroborate one another.
• Observe at least one related task or alarm cycle to confirm that the issue does not recur.

Risks and rollback

• Before remediation in production, confirm customer service impact, the change window, and the rollback plan.
• For data deletion, database modifications, snapshot-chain repairs, underlying file operations, or hardware operations, ZStack recommends contacting technical support for confirmation.

Notes

• For VM startup, migration, HA, Unknown status, or forced stop operations, first confirm the actual VM running location to prevent split-brain operation, dual writes, or unintended service interruption.
• For management networks, storage networks, service networks, DHCP/VNC, VLANs, bonds, port groups, or switch-side settings, retain an available management channel and preferentially perform changes during a maintenance window.
• If database modifications, underlying file operations, lock release, service restarts, driver or firmware upgrades, or bulk resource changes are required, contact ZStack technical support before proceeding.