VMware Log Insight – Duplicate Hosts Listed

After returning from a VMware Design course and having learned that Log Insight was now free to valid vCenter licence holders, I set straight to work deploying it into our development environment. However, despite having under 25 hosts Log Insight soon started complaining about exceeding the allowed 25 OSI limit. ESXi hosts were being displayed in the statistics with both their defined hostname, but also what appeared to be their FQDN (e.g. vmhosta-01 and vmhosta-01.domain.com).

Checking on the hosts themselves (esxcli system hostname get) there was no domain or FQDN set, but they do have FQDNs in DNS, and vCenter knows them by their FQDN.

To fix the issue, I made things consistent by setting the domain and FQDN on all hosts using PowerCLI:

$vmhosts | Get-VMHostService | Where-Object -FilterScript { $_.key -eq 'TSM-SSH' } | Start-VMHostService
$vmhosts | % {
    $esxcli = Get-EsxCli -VMHost $_ 
    $esxcli.system.hostname.set($null,$($_.name),$null) 
    Start-Sleep -Seconds 3 
    $esxcli.system.hostname.get()
}
$vmhosts | Get-VMHostService | Where-Object -FilterScript { $_.key -eq 'TSM-SSH' } | Stop-VMHostService

You can verify whether the change has helped quite easily, by visiting: https://your-loginsight/admin/hosts – the ‘Last Received Event’ for hosts without FQDNs simply growing greater and greater. After 12 hours, the ‘Average Active OSIs’ (as reported by https://your-loginsight/admin/license) had dropped slightly, but it’s got a way to go before being under 25.