vSAN Health Service - Unicast agent not configured
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vSAN Health Service - Unicast agent not configured

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Article ID: 326871

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Updated On:

Products

VMware vSAN

Issue/Introduction

The Unicast agent not configured check in the vSAN Health Service verifies that each data site host has a unicast agent configured. The unicast agent enables the data host to communicate with the witness host in the stretched cluster.

If this health check is not green (OK), the vSAN stretched cluster has configuration issues that affect its operation.

Environment

VMware vSAN 6.0.x
VMware vSAN 6.2.x
VMware vSAN 6.1.x

Resolution

To troubleshoot and resolve configuration errors:
  1. Configure the unicast communication between the data site host and the witness host so that the IP address and port are configured consistently on all hosts.
    • To verify the listening IP address and port used by the witness host, run the esxcli vsan network list command. To avoid confusion, use only one interface configured for vSAN traffic. The witness host uses the first available vSAN network interface to listen for unicast IP traffic.
    • To configure the listening address of the witness host on a host in a data site, run the esxcli vsan cluster unicastagent list command. Currently only one unicast agent address is supported.
    • A host should not have have itself in its own unicast table.
  2. Configure the unicast agent with the IP address and port of the witness host. Every host in the data sites uses its unicast agent to communicate with the witness host.
  3. Configure all hosts in each data site with the same IP address and port for the unicast agent. All hosts in a stretched cluster must have a consistent configuration.
  4. For more details about how to configure the unicast table, please refer to  https://kb.vmware.com/s/article/2150303

Additional Information

To view the list of ESXi hosts, run the esxcli vsan cluster get command. If you run the command on the witness host, the local node type appears as WITNESS.

For example:

[root@:~] esxcli vsan cluster get
Cluster Information
Enabled: true
Current Local Time: 2015-06-25T23:52:26Z
Local Node UUID: 558c3ca0-e92f-c784-8b00-020001ff8d0e
Local Node Type: WITNESS
Local Node State: AGENT
Local Node Health State: HEALTHY
Sub-Cluster Master UUID: 558c3ca0-0439-2d57-8994-0200011a27e7
Sub-Cluster Backup UUID: 558c3ca0-1a32-1527-2847-020001469e57
Sub-Cluster UUID: 526a9252-9d60-5893-d523-c3cbeb61e1bb
Sub-Cluster Membership Entry Revision: 2
Sub-Cluster Member Count: 3
Sub-Cluster Member UUIDs: 558c3ca0-0439-2d57-8994-0200011a27e7, 558c3ca0-e92f-c784-8b00-020001ff8d0e, 558c3ca0-1a32-1527-2847-020001469e57
Sub-Cluster Membership UUID: 90418c55-1ba1-5615-44ac-0200011a27e7

 

You can collect the list of node information and preferred fault domain by querying CMMDS from a host.

For example:

[root@:~] cmmds-tool find -t NODE

owner=00000000-0000-0000-0000-000000000000(Health: Healthy) uuid=558c3ca0-1a32-1527-2847-020001469e57 type=NODE rev=0 minHostVer=0 [content = (i2 i1 i0 i1 i0)], errorStr=(null)

owner=00000000-0000-0000-0000-000000000000(Health: Healthy) uuid=558c3ca0-0439-2d57-8994-0200011a27e7 type=NODE rev=0 minHostVer=0 [content = (i2 i1 i0 i1 i0)], errorStr=(null)

owner=00000000-0000-0000-0000-000000000000(Health: Healthy) uuid=558c3ca0-e92f-c784-8b00-020001ff8d0e type=NODE rev=0 minHostVer=0 [content = (i2 i1 i3 i1 i0)], errorStr=(null)



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