Memory pressure is a "metric" (don't you just love those buzz words?).
Essentially, say you've got a bunch of virtual machines on a given server. You've got, oh, 16G RAM in the box. You allocate maybe 4G RAM to each virtual machine. You start up two of 'em (so 8G RAM is used by the virtual machines and you've got 8G RAM for the server operation system); no pressure there. Start another and you're up to 12G virtual and 4G system, still not too much. Start another and the whole thing comes crashing down (because the system will be swapping like mad and things grind quickly to a halt). That's memory pressure -- you allocate too much memory to too many things and you spend all your time swapping (we used to call that trashing).
The lesson is that you need more RAM to support more virtual machines (or more applications).
Memory pressure is reported by nworks
, and appears to be useful with VMware
. Take a look at the link for more information.
But, you can save yourself a lot of trouble by simply figuring out what you need to support what you're doing and make sure there's sufficient capacity to do so -- things like enough RAM (number one) and spreading the load over multiple servers.
Hope this helps some.