据我所知，从单AZ升级到多AZ RDS的时候，出现了breef I / O冻结。这到底是什么意思呢？

在升级是由一个多AZ部署，从小到大说，将生产数据库将在所有受影响？它能否使用备份DATABSE，那么故障转移？

问题的答案都写下来：

当您选择从单AZ到多AZ移动，短暂的I / O冻结情况。这意味着，对于一些持续时间数据库将无法访问。不读，写操作将在数据库上执行。大多数情况下，在持续时间，这是大约3-4分钟。

是的，生产数据库将当调整计算（从小到大）会受到影响。执行调整大小操作最好的办法是在预定的维护窗口。如果选择立即应用选项，为某个数据库将无法访问（时间控制切换到备份服务器）。

问候， SANKET Dangi

I understand that when upgrading to a Multi-AZ rds from a Single-AZ, there occurs a "breef i/o freeze". What exactly does that mean?

When an upgrade is made to a Multi-AZ deployment, say from small to large, will the production database be impacted at all? Will it be able to use the backup databse, then failover?

Answers to your questions are written down :

When you choose to move from Single AZ to Multi AZ, brief I/O freeze happens. It means that for some duration database won't be accessible. No read,write operations will be performed on the database. Mostly, the duration for this is around 3-4 minutes.

Yeah, production database will be affected when you resize the compute(from small to large). The best idea to perform resize operation is during scheduled maintenance window. If select Apply Immediately option, for sometime the database won't be accessible(time to switch control to backup server).

Regards, Sanket Dangi