VMs configured with VMHA should be migrated to another storage and kept running when the primary storage is put on maintenance.

### The required feature described as a wish

When a primary storage is put on maintenance, the systemVMs are migrated to another primary storage and all user VMs are stopped. The user VMs are migrated on demand when they are manually started.

This might not be the intended behaviour for Instances on which VMHA is enabled and which are expected to by highly available. We might add a global config which will control if the Instances configured with VMHA are automatically migrated and are kept running.

Creating this issue to discuss and track this feature request.

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Discussed on https://github.com/apache/cloudstack/issues/12215
From the documentation https://docs.cloudstack.apache.org/en/4.22.0.0/adminguide/storage.html#maintenance-mode-for-primary-storage
`it will stop all guests that have any volume on that storage device.`

从链接的主存储维护文档和 issue #12215 开始；该内容没有列出任何实现文件或测试。明确 VMHA 实例的全局配置和预期行为，包括迁移以及保持 VM 运行，然后定义能够展示约定结果的测试或文档。

由索引模型根据 Issue 内容生成。