I have a standalone IBM x3400 server configured as host with ESX4. I installed 3 VM:
VM1: Windows server 2003 R2 - Secondary domain controller
VM2: Windows server 2003 R2 - Application server
VM3: Windows server 2008 R2 - Virtual Center Server
All works fine since 2 weeks ago when I cant access the host throught Virtual Center Server and vSphere client.
In virtual center I have this error: Unable to connect to MKS: vim.fault.nohost.
The host service console in unaccessible, I cant log in as root.
VM1 is not running, VM2 and VM3 seems work correctly.
What can I do without create a disaster??
You might want to open a case with VMware. But if you can't access the host at all, I'd find a time when you can shut down the two running VMs via RDP and then restart the host server. Once it is up bring up your VMs again.
I had a same problem and unable to access the ESX console through console as well, i did a hard reboot and power ON the VM's again, its working absolutely fine.
regards,
I have recently got this issue with ESXi 4.1 Host and found an error in the Summary of the Host stating "Cannot able to synchronize Host XXX. Cannot able to login due to incorrect username and password"
The error vanished and can able to take console of the VMs from vCenter.