Click through for the details, but here are the highlights. Link: VMware: VI Team Blog: Top Tips for Deploying VI, part 2.
1. If you have an active/passive FC storage array (most
mid-range arrays fall into this bucket), be careful about setup.
Firstly, be sure to have redundant paths from FC switches to your
arrays’ storage processors. Secondly, be sure to use “MRU” (the
default) for the path-selection policy and not “fixed”.2. When configuring your VI environment for VMotion, make sure
that your physical network switches are configured properly; in
particular, make sure that each port has the right network (e.g. VLAN)
visibility.3. When using VMware HA, take note of how memory reservations
are specified and used to reserve cluster failover capacity. Using
more consistent reservations or disabling admission control are both
appropriate workarounds if the calculations are overly conservative in
your environment.4. When sizing your LUNs, a medium-sized LUN (~500GB) seems best for most situations.
Also don’t miss Top Tips for Deploying VI, Part 1