Cannot Open Datafile
With innodb_file_per_table enabled (the default), the following messages may appear at startup if a file-per-table tablespace file (.ibd file) is missing:
[ERROR] InnoDB: Operating system error number 2 in a file operation.
[ERROR] InnoDB: The error means the system cannot find the path specified.
[ERROR] InnoDB: Cannot open datafile for read-only: './test/t1.ibd' OS error: 71
[Warning] InnoDB: Ignoring tablespace `test/t1` because it could not be opened.
To address the these messages, issue DROP TABLE statement to remove data about the missing table from the data dictionary.