While I totally understand the use case, I think this is a new feature for performance reasons and not a bug. CLosing it as Wishlist but of course you can work on it if you wish ;)
** Changed in: nova Importance: Undecided => Wishlist ** Changed in: nova Status: New => Invalid -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to OpenStack Compute (nova). https://bugs.launchpad.net/bugs/1887377 Title: nova does not loadbalance asignmnet of resources on a host based on avaiablity of pci device, hugepages or pcpus. Status in OpenStack Compute (nova): Invalid Bug description: Nova has supported hugpages, cpu pinning and pci numa affintiy for a very long time. since its introduction the advice has always been to create a flavor that mimic your typeical hardware toplogy. i.e. if all your compute host have 2 numa nodes the you should create flavor that request 2 numa nodes. for along time operators have ignored this advice and continued to create singel numa node flavor sighting that after 5+ year of hardware venders working with VNF vendor to make there product numa aware, vnf often still do not optimize properly for a multi numa environment. as a result many operator still deploy single numa vms although that is becoming less common over time. when you deploy a vm with a single numa node today we more or less iterate over the host numa node in order and assign the vm to the first numa nodes where it fits. on a host without any pci devices whitelisted for openstack management this behvaior result in numa nodes being filled linerally form numa 0 to numa n. that mean if a host had 100G of hugepage on both numa node 0 and 1 and you schduled 101 1G singel numa vms to the host, 100 vm would spawn on numa0 and 1 vm would spwan on numa node 1. that means that the first 100 vms would all contened for cpu resouces on the first numa node while the last vm had all of the secound numa ndoe to its own use. the correct behavior woudl be for nova to round robin asign the vms attepmetin to keep the resouce avapiableity blanced. this will maxiumise performance for indivigual vms while pessimisng the schduling of large vms on a host. to this end a new numa blancing config option (unset, pack or spread) should be added and we should sort numa nodes in decending(spread) or acending(pack) order based on pMEM, pCPUs, mempages and pci devices in that sequence. in future release when numa is in placment this sorting will need to be done in a weigher that sorts the allocation caindiates based on the same pack/spread cirtira. i am filing this as a bug not a feature as this will have a significant impact for existing deployment that either expected https://specs.openstack.org/openstack/nova- specs/specs/pike/implemented/reserve-numa-with-pci.html to implement this logic already or who do not follow our existing guidance on creating flavor that align to the host topology. To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/1887377/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : yahoo-eng-team@lists.launchpad.net Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp