Nutanix CE 上の Prism Central が起動できなくなってしまったので、下記の KB を参考に、強制的に Prism Element から削除してみます。
※ただし、本番環境の Nutanix では気軽に実施せず、ちゃんと製品サポートに問い合わせしたうえで作業を開始するとよいかなと思います。
それでは、CVM に SSH でログインして作業します。まず、ncli コマンドで Prism Central の Cluster ID を確認します。
nutanix@NTNX-7e2b5cd3-A-CVM:192.168.20.52:~$ ncli multicluster get-cluster-state
Registered Cluster Count: 1
Cluster Id : 47603a98-c888-4f6a-a7b6-86210c312ad1
Cluster Name : Unnamed
Is Multicluster : true
Controller VM IP Addre... : [192.168.20.15]
External or Masqueradi... :
Cluster FQDN :
Controller VM NAT IP A... :
Marked for Removal : false
Remote Connection Exists : true
ncli コマンドで、Prism Central の Cluster ID を指定して登録を削除します。
nutanix@NTNX-7e2b5cd3-A-CVM:192.168.20.52:~$ ncli multicluster delete-cluster-state cluster-id=47603a98-c888-4f6a-a7b6-86210c312ad1 Cluster state deleted successfully
Prism Central の登録が解除されました・・・

一応、クリーンアップ スクリプトを実行しておきます。
nutanix@NTNX-7e2b5cd3-A-CVM:192.168.20.52:~$ python /home/nutanix/bin/unregistration_cleanup.py 47603a98-c888-4f6a-a7b6-86210c312ad1
-------- Script to perform custom cleanup actions post unregistration ---------
Invoking handlers for cleanup of cluster
{'REMOTE_CONNECTION_SERVICE': 'pe_pc_rc_cleanup_handler'}
Invoking handler pe_pc_rc_cleanup_handler
========================================================
CLEAN UP OF STALE PE PC RC ENTITIES BEING PERFORMED
========================================================
FROM ZK NODE - EXTERNAL CLUSTER UUIDS: []
-----------------------------------------------
THERE ARE NO RC ENTITIES TO BE CLEANED UP.
CLEANUP COMPLETED
-------- Results of cleanup by different handlers ---------
[('REMOTE_CONNECTION_SERVICE', { 'message': 'Success', 'status': True})]
Clean up backup data for PC Cluster 47603a98-c888-4f6a-a7b6-86210c312ad1 requested.
PE and PC are unregistered. Waiting 60 secs so all pending sync calls would be done.
Cleaned up 0 backup entities in total.
Cleared replication states for PC cluster : 47603a98-c888-4f6a-a7b6-86210c312ad1.
Verified that entities are purged from Cassandra.
SUCCESSFULY CLEANED UP BACKUP DATA FROM PE.
Successfully completed cleanup actions for cluster 47603a98-c888-4f6a-a7b6-86210c312ad1
Exception AttributeError: "'NoneType' object has no attribute 'SHUT_WR'" in > ignored
ふりだしに戻る。
