This page describes how guarantees for resources can be implemented.
= How to guarantee a guarantee =It's not obvious at the first glancecomment2, but ''there are only two ways of how a guarantee can be provided'':# reserve desired amount in advance# limit consumers to keep some amount free The first way has the followong disadvantages:; Reservation is impossible for certain resources: such as CPU time, disk or network bandwidth and similar can not be just reserved as their amount instantly increases; ; Reserved amount is essentially a limit, but much more strict: cutting off X megabytes from RAM implies that all the rest groups are limited in their RAM consumption; ; Reservation reduces containers density: if one wants to run some identical containers, each requiring 100Mb on 1Gb system, reservations can be done for only 10 containers, and starting the 11th is impossible. On the other hand, ''limiting'' of containers can provide guarantees for them as well.
= Providing a guarantee through limiting =