- VMware 상의 RHCS(Pacemaker)구성 환경에서 Node VM vMotion(Live Migration)과 관련된 주의 사항
vMWare 상의 레드햇 클러스터로 조인된 node의 vMotion을 지원하지 않는다는 내용으로 아래 Articles 참고. (2019.12.29 기준)
Design Guidance for RHEL High Availability Clusters - VMware Virtual Machines as Cluster Members
https://access.redhat.com/articles/3349791
아래는 3349791 articles 내용 일부임
VM administration requirement: Prevent live migration while VM is active in cluster
Additional details:
See: Support policies - General conditions with virtualized cluster members
If using DRS VM-host affinity (as in above recommendation), live migration is prevented.
If manually administering VM distribution across hosts, or if not using DRS VM-host affinity - ensure policies and practices prevent any live migration while a VM is active. Always stop the RHEL HA cluster services (pcs cluster stop) before migrating any VM.
Reasons:
- Active 상태인 클러스터 노드를 vMotion 시 3가지 이슈가 발생할 수 있으므로 수동으로 cluster를 중지 후 vMotion을 수행하여야 함.
*Live migration introduces a pause in VM processing, which can disrupt High Availability membership (and is often observed to, in real production environments). This pause is unpredictable and configuring HA to definitively avoid it is difficult.
: vMotion 시 VM 응답 지연에 의해 이슈 발생 가능성
*Live migration by vMotion takes special measures to update multicast group registration of VMs at their new host. This has not been assess by Red Hat to determine if RHEL High Availability's udp (multicast) transport protocol is compatible with these measures.
: vMotion 후 H/B 통신을 위한 멀티캐스트 그룹 등록 업데이트 이슈 발생 가능성
*Live migration may cause any static STONITH configuration host <-> VM mappings in the cluster to become incorrect. Even if there is a plan to update STONITH configuration before or after migration, there would be a period either at the front-end or back-end of the migration where STONITH settings would be incorrect and STONITH could fail if the VM became unresponsive - potentially blocking cluster operations.
: vMotion 후 STONITH (fence_vmware_soap 장치 등)의 불일치 발생 가능성
- 추가 참고 자료
Support Policies for RHEL High Availability Clusters - General Conditions with Virtualized Cluster Members
https://access.redhat.com/articles/3131111
Red Hat does not test live migration of cluster nodes running on any virtualization technology, and thus live migration is not officially supported.
이유는 현재 RedHat에서 Live migration하에서의 Cluster동작 관련 테스트를 하지 않아서 이며, 해당 부분은 Red Hat RHV(RHEV)에서도 같음
Support Policies for RHEL High Availability Clusters - fence_scsi and fence_mpath
https://access.redhat.com/articles/3078811