又找到一位大神的博客
http://blog.chinaunix.net/uid-20940095-id-4064233.html
http://blog.chinaunix.net/uid-20940095-id-3875022.html
大神在博客里说的很清楚了,总结一下
Availability Zone 主要是用来容灾的,人为的将机器分为不同的zone,比如根据地点,将机器分为若干的zone,是为了不让机器一起同时挂掉...(本以为是要做HA的)
博客里看到这一句话:
AZ之间共享所有的nova服务和keystone服务
这就是说 Zone划分的只是Nova-Compute服务,即计算节点
而Host Aggregates是则是将节点根据某一个属性来划分为一组,比如将Compuete节点根据CPU的类型划分为一个aggregate,这样可以在这个Aggregate来进行life Migration;
将有SSD属性的节点作为一个Aggregate,可以将有数据库服务的VM放到这个Aggregate上。
Manual中有这一段话:
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. Host aggregates
started out as a way to use Xen hypervisor resource pools, but has been generalized to provide a mechanism to allow administrators to assign key-value pairs to groups of machines.
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. This information can be used in the scheduler to enable advanced scheduling, to set up Xen hypervisor
resources pools or to define logical groups for migration
一个节点可以被划分到多个aggregates ,即一个节点 既可以是属于CPU为X5570的aggregates ,也可以是属于有SSD的aggregates ,
最终还是用于Scheduling的