It's not obvious at the first glance, but ''there are only two ways of how a guarantee can be provided'':# reserving reserve desired amount in advance# limiting limit consumers to keep some amount free

; reserving Reservation is impossible for certain resources: such resources as CPU time, disk or network bandwidth and similar can not be just reserved as theirs their amount instatntly instantly increases;

; reserving 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 theirs their RAM consumption;

; reserving Reservation reduces containers density on the node: if one wants to run some identical containers , each requiring 100Mb on 1Gb system , reservations can be done for only 10 only containers, and starting the 11th becomes is impossible.

On the other hand , ''limiting'' of containers can provide guarantees for them as well.