Define a server-wide data limit and restrict data limits on all keys to fall within that total amount

[QingXXiong]

What's wrong

No control over the total data transferred for a server. It's easier and safer to set a data limit for a server no matter how many keys exist.

What to improve

Enforce the 'Data Limit' value for a server to each access key. That's, the 'Data Limit' value for a key can't be higher than the value for a server. Also, if multiple keys exist, for creating a new key, remind the remaining data limit for this key to use. For example, you have an X server with a data limit value of 80 GB, and you have three keys with a 10 GB data limit for each. Now, you want to create another key, then this key can't have a data limit of > 50 GB. This value should be a default value for the Data Limit field. Also, if the data limit value is higher than it, an error message should show.

I think the current features for data limit may be a subset of what I described. That's, for the current feature, you have infinite data to transfer for a server, so you enforce the infinite 'Data Limit' value for all keys.