VMware · TROUBLESHOOTING

VMware vSAN Network Troubleshooting: Partition and Packet-Loss Checklist

Troubleshoot vSAN network partitions, packet loss, heartbeat timeouts and hosts dropping in and out of the vSAN cluster.

Practical Runbook7 StepsIssues → Solutions → Recommendations
!Issue

Troubleshoot vSAN network partitions, packet loss, heartbeat timeouts and hosts dropping in and out of the vSAN cluster.

Solution

01 Check vSAN VMkernel configuration

Recommendations

07 Confirm recovery After correcting the network, verify vSAN health, cluster membership and object accessibility before closing the incident. Useful commands esxcli vsan cluster get vmkping -I vmkX <peer-vSAN-IP> esxcli network nic list esxcli network nic stats get -n vmnicX Production workflow: capture the current state, test the dependency directly, make one controlled change, retest the original symptom and document the evidence. Quick checklist Check vSAN VMkernel configuration Check end-to-end reachability Look for packet loss Check membership changes Review vmkernel and vobd logs Validate the physical network Confirm recovery Primary r…

Verify that every participating host has the intended VMkernel adapter enabled for vSAN traffic and that the correct network is attached.

01

Check vSAN VMkernel configuration

02

Check end-to-end reachability

Test host-to-host communication over the vSAN network. Validate VLAN configuration, MTU and physical uplinks rather than testing only management connectivity.

03

Look for packet loss

Packet loss and timeouts can cause heartbeat failures and cluster partitions. Check switch counters, NIC errors and physical links when the symptom is intermittent.

04

Check membership changes

Use esxcli vsan cluster get and vSAN health information to determine whether hosts are repeatedly joining and leaving the cluster.

05

Review vmkernel and vobd logs

Look for network-card errors, heartbeat timeouts and communication failures around the exact incident time.

06

Validate the physical network

Check the switch ports, VLANs, LACP configuration if used, MTU consistency and redundancy. vSAN depends on reliable host-to-host communication.

07

Confirm recovery

After correcting the network, verify vSAN health, cluster membership and object accessibility before closing the incident.

Useful commands

esxcli vsan cluster get
vmkping -I vmkX <peer-vSAN-IP>
esxcli network nic list
esxcli network nic stats get -n vmnicX
Production workflow: capture the current state, test the dependency directly, make one controlled change, retest the original symptom and document the evidence.

Quick checklist

  • Check vSAN VMkernel configuration
  • Check end-to-end reachability
  • Look for packet loss
  • Check membership changes
  • Review vmkernel and vobd logs
  • Validate the physical network
  • Confirm recovery

Primary reference

This TechRunbook guide is independently written and cross-checked against Broadcom VMware documentation. View the reference →

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