How to tell if you are out of space in esxi:
Scenario. Perhaps you build a cluster and after dragging the host into the cluster, the agent fails to install.
Note: Running grep -i full /var/log/hostd.log would show the following...
Note: Other logs like /var/log/vmkernel.log would show the same type of information
How to verify: Run the vdf -h command ... and notice in this case /tmp is almost full...
Note: There are other cool commands that can help you see this. The stat command shows few blocks left.
Notice: The df -h command does not help you... :(