Difference between "pool", "host" and "server".

ZaphodB

Hi there,

I'm a noob and very excited about XCP-ng and (open source) XOA. I've been playing around with a simple setup on my home lab for a week or so now. I'm also new to the forum, so if this topic should be in another category, let me know, and my apologies up front.

One question that I can't seem to get my head around is the terminology used in various places.

In Xen Orchestra under the home menu, I have "pools" which have "hosts". In "settings" I also have "servers".

What is the difference between "servers" and "hosts" in a pool?

I asked because I have one pool with two hosts, but only one server. If I try to add the other host under servers it fails with the kind of cryptic message "this pool is already connected". Can there be only one "server" in a pool?

The xcp-ng display when a monitor is attached to a host talks about a "Resource pool". Is this the same as a "pool" in Xen Orchestra?

Cheers, ZaphodB

ravenet

Pool is resource pool, yes.

pool can consist of multiple hosts which can live migrate VMs

Server = host

andrewperry

@ZaphodB I have the same experience some 2.5yrs later - I don't know why there isn't some more clarity in XO as to what and when you should add a machine as a "Server" under settings. When I installed XCP-NG on my second 'host' it joined the pool but wasn't added in XO as a "Server".

pdonias

Hi @andrewperry, a "server" in XO 5 represents a "connection to a pool". Since you need to enter your physical server's information, that's why we called it that way. But we agree too much vocabulary can be confusing so in XO 6 we'll change that and probably call it something like "Pool connections".

andrewperry

@pdonias nice - so I gather we can delete from the 'server' settings the secondary host that we tried adding there, but is showing an error.

From what you say, I gather the 'pool connections' is for master servers of pools so there should just be one in the settings for each pool?

pdonias

@andrewperry Exactly