Dave,
Thanks for the blisteringly fast reply, in a time that Ping requests could be proud of!
I reinstalled ESXi, wondering whether I could have somehow made a detrimental configuration change during my learning stages. I've also made the changes you linked to. Whilst I have noticed a positive effect (some memory being released and made available for me to actually use!) the maths still doesn't quite add up.
Memory usage now reported as : 693Mb
(Resource Allocation) Memory Total Capactity 978Mb
...which still leaves ~400Mb missing. Where is it? Have you got it?
If the answer is simply "The system is using it" then I guess I'll accept that - although it would mean that without any VMs running the system 'costs' ~1200Mb to run. I see that the child objects in the init level of the vmvisor also have memory reservations. Are these all adding up to account for the missing memory, or are their collective memory requirements satisfied by their parent level ("init") or indeed the grandparent level, "vmvisor", that I just changed the setting for?
Thanks again and in advance..