[Beowulf] New member, upgrading our existing Beowulf cluster

[Mark Hahn]

>> depends on your max job length.  but yeah, idling three nodes for a week
>> is not going to be noticable in anything but a quite small cluster...
>
> But doesn't the engineer in you just bristle at the (admittedly, rather 
> slight) inefficiency?  Call me OCD (you wouldn't be the first), but it just 
> bugs me.

well, what I prefer to do is set a reservation on the node 
that starts one max-job-period in the future.  that means shorter jobs 
get to use the node until then.

ultimately, it depends both on how much individual hotpluggability costs
(the HW changes don't sound trivial to me) as well as the joblength/etc.
I doubt I'd choose to pay more than a few percent for HPability,
assuming 2-4 nodes-per-box and ~<7d job limits...