Have been looking at an ESX 4.1 cluster recently in which one host was being a bit truculent. After a BIOS upgrade the host seemed to be behaving itself so after a couple of weeks of stress testing with no issues I added it back into the cluster.
However, nothing would migrate to it and I eventually tracked down three separate issues (note to self):
- Moving hosts between clusters can confuse the standard switch configuration. You really need to re-create the standard switches each time you add to a cluster.
- An I/P address was wrong (typo)
- The hash of the NFS datastore UUID was different. On the other hosts in the cluster the datastore had been added with I/P address and on this one it had been added with NFS server name. ESX essentially thought they were different datastores as 4.1 uses a crude hash to create a UUID (I would have though it should pick up a UUID from the datastore itself).