You cannot increase the size of an existing system tablespace data file by changing its size attribute. For example, changing the innodb_data_file_path setting from ibdata1:10M:autoextend to ibdata1:12M:autoextend produces the following error when starting the server:
报错信息如下：
[ERROR] [MY-012263] [InnoDB] The Auto-extending innodb_system
data file ‘./ibdata1‘ is of a different size 640 pages (rounded down to MB) than
specified in the .cnf file: initial 768 pages, max 0 (relevant if non-zero) pages!
The error indicates that the existing data file size (expressed in InnoDB pages) is different from the size specified in the configuration file. If you encounter this error, restore the previous innodb_data_file_path setting, and refer to the system tablespace resizing instructions.
默认参数如下：
innodb_data_file_path=ibdata1:12M:autoextend
想直接resize系统表空间，如下调整会直接报错。
innodb_data_file_path=ibdata1:100M:autoextend
查看官方文档
https://dev.mysql.com/doc/refman/8.0/en/innodb-system-tablespace.html
原文：https://blog.51cto.com/roidba/2452822