ESX 3.0 Host not responding ?

It might be because the host daemon or the virtualcenter agent has crashed. Follow the instructions in the article to check or restart them.

Cannot log into ESX 3.0 host via putty, winscp, the mui or ssh as root ?

More than likely because ESX is secure by default and does not allow it.
To change it modify the /etc/ssh/sshd_config file and change "PermitRootLogin no" to "PermitRootLogin yes"
You will need to do this via VI on the console. Follow the steps below.

If you have upgraded a large number of Virtual Machines from ESX 2.x to ESX 3 you may find it easier to do a batch upgrade of VMware tools than to do them individually.The batch upgrade command can be found on the VirtualCenter server in the "c:\program files\vmware\vmware virtualcenter 2.0" directory and the syntax is :

vmware-vmupgrade.exe -u <user> -p <passwd> -n "cluster-name/VM-name"

for example

vmware-vmupgrade.exe -u administrator -p password -n "mybigdatacenter/quickvm"

So I have completed my first ESX 3.0 upgrade even if it only a dev host! As stated in the previous article, we upgraded virtualcenter to 2.0 which went relatively smoothly and then I proceeded on to a clean install of ESX 3.0 on my dev host. Before I could do this I had to migrate the dev servers off the host to another location. This is the basic steps that the upgrade took on it's way to completion. There are some tips and tricks from this upgrade that I would like to share for the regular readers of this blog, so read on.