Sorry about not being clear let me try to clear it up:
>you can present NFS to ESXi then other hosts.
->Do you mean I can create an NFS datastore through the vSphere client and have the ESXi host on that machine run a NFS server? If so that would be ideal but I've not been able to find how to do that, could you point me in the right direction?
No sorry I do not. ESXi has not ability to be a NFS server in any way. You would need to have a NFS server(not ESXi Linux, unix etc) present storage to ESXi then that same storage could be presented to other hosts via NFS... be careful with that thou it could cause some funky locking.
>you can share via VMFS of course.
Do you mean by using VSA or were you referring to something else?
VMFS datastores can be shared with as many ESXi hosts as you like up to configuration maximum.
Honestly If I understood better what you are trying to do I could better answer your questions... let me ask a few questions to help frame the solution:
I have a datastore on an ESXi 5.1 host that I'd like to make accessible via NFS or FTP so that other hosts can see its contents
-> What other type of hosts? (ESXi, Linux, Unix, Windows etc..)
-> What do you plan on doing with the Files once presented to the other hosts?
In the back of my mind I wonder if your working on some type of backup solution or something... Help me understand more so I can assist you.
Thanks,
J