ceph multisite

参考：

multisite介绍：https://www.jianshu.com/p/31a6f8df9a8f

配置：https://blog.csdn.net/for_tech/article/details/68927956

论文：https://ceph.com/wp-content/uploads/2017/01/Understanding-a-Multi-Site-Ceph-Gateway-Installation-170119.pdf