如果创建一个不存在的primary storage，虽然报错，但是在UI上显示Enabled

[lstfyt]

如果创建一个不存在的primary storage，虽然API报错，但是在UI上显示Enabled，容量为空。
只是cluster上显示为空。
期望结果：API报错，primary storage创建不成功，UI不显示，

{
"org.zstack.header.storage.primary.APIAttachPrimaryStorageToClusterEvent": {
"success": false,
"apiId": "ed574bfb60be4beb9314654d0016a4b1",
"headers": {
"schema": {}
},
"error": {
"code": "PS.1001",
"cause": {
"code": "SYS.1006",
"description": "An operation failed",
"details": "failed to execute shell command: mount 192.168.0.212:/usr/local/zstack/nfs_root /opt/zstack/nfsprimarystorage/prim-67e94e2c0e1748c4984f78d7810b79ef\nreturn code: 32\nstdout: \nstderr: mount.nfs: Connection timed out\n"
},
"description": "Unable to attach a primary storage to cluster",
"details": "failed to execute shell command: mount 192.168.0.212:/usr/local/zstack/nfs_root /opt/zstack/nfsprimarystorage/prim-67e94e2c0e1748c4984f78d7810b79ef\nreturn code: 32\nstdout: \nstderr: mount.nfs: Connection timed out\n"
},
"id": "3df9a32d6574465c8bb532cb2612089c",
"creatingTime": 1454074822674
}
}

[lstfyt]

否则只能在最后VM 创建时，才会显示错误，而且不易发现。

[youyk]

add host 就会出错的

[lstfyt]

如果等待host添加正常，等结果返回了，再添加primary storage 并不会提示add host error。