Here are a couple useful reads:
http://storagefoo.blogspot.com/2007/09/vmware-over-nfs.html
http://blog.scottlowe.org/2007/09/21/nfs-for-vmware-storage/
Note with RAID5 you'll have an IO problem over the network. If it's just a one node cluster local disk is fine. Main reason to go network...
Write latency is always the killer for NAS. With iSCSI you need to consider the IO queue limits. With NFS you need to have a fast response sync mount.
A spinning disk (single stripe say) can do 100 iops on a 64k packet, or about 6MB/s. A write cache will speed this up. Or example a pair of...
Putting together a basic 1U colo system for ESXi.
Supermicro 5016T-MTF
Xeon E5620
12GB RAM
RAID10 - 4xSeagate Constellation ES SAS
I'm trying to decide between the 2405 and the 5405z. The 5405z is a 5405 with a BBU, there is no BBU option for the 2405. Both units are in the ESXi HCL...