Common problems with host preparation are:
- EAM fails to deploy VIBs
- Might be DNS issues
- Might be Firewall
- Might be VUM vs. EAM issues
- Previous VIBs might be installed (** from 6.3.0 onwards this shouldn’t be an issues) if this is an issue the hosts might require a reboot.
- vCenter Networking and Secuity Plugin might be playing up.
There a re some basic checks we can do which I’ll go through below:
1. Log into the Web Client.
2. Click Networking and Security.
3. Click Installation, then Host Preparation. This will show all vCenter Server cluster and hosts. I’m working through this blog series using VMware Hands On Labs… so as expected my hosts are all green and healthy!)
If you have a cluster with a red stop error (Not Ready) then you will have to resolve those issues, if you click on the Not Ready link you will get a decent description of what is wrong with any hosts in that cluster with errors. Most of the issues I have seen can be resolved with either restarting the VUM server or restarting ESXi hosts.
You can also check the Communication Channel Health to do this run this option on either the cluster or host level: