OpenStack Xenserver Host Aggregate 建置筆記

所謂的Xenserver Host-Aggregte目的是為了讓Compute Node能利用Xensever Resource Pool的概念集結起來，在掛載像是NFS Share的SR以便做Live-migration或是VM-RESIZE。

1. 在XenServer Host上先製作出PV的Nova Compute Node + quantum-plugin-openvswitch-agent
    (ubuntu 12.04 LTS )
2. 然後再將要建置成resource pool的所有compute node中的/etc/nova/nova.conf加入以下的設定:
    sr_matching_filter =  default-sr:true

3. 再來利用aggregate-create在availability zone中建置邏輯資源池(logical resource pool)
    nova aggregate-create <pool-name>  <availability-zone>

4.  再來設定host-aggregate的metadata，告訴nova controller我要建置的是xenserver resource pool:
   nova aggregate-set-metadata <pool-id>  hypervisor_pool=true
   nova aggregate-set-metadata <pool-id>  operational_state=create

5.  從所有的計算節點當中選出一個當作Master ComputeNode:
  nova  aggregate-add-host <pool-id> <master-compute-node>

6. 其他後續加入的compute node會成為slave compute node:
nova aggregate-add-host <pool-id>  <slave-compute-node>



Reference:
1. http://docs.openstack.org/trunk/openstack-compute/admin/content/configuring-migrations.html#true-live-migration-kvm-libvirt

Host Aggregate : 用來在availability zone中進行劃分

Host aggregates are a mechanism to further partition an availability zone; while availability zones are visible to users, host aggregates are only visible to administrators. 

[Note]

Each node can have multiple aggregates, each aggregate can have multiple key-value pairs, and the same key-value pair can be assigned to multiple aggregate.

Xenserver

當使用Xenserver當作hypervisor時，可以使用host-aggregate來管理Xenserver Resource Pool以支援Live migration。