When encountering the MySQL error "1137: Error writing file," a user should immediately perform the following actions for investigation:
- Check Disk Space: Often, this error is due to insufficient disk space. Run the command `df -h` to check available disk space on the server. If the disk is full, consider freeing up space or expanding the disk.
- Check File Permissions: Ensure the MySQL user has the necessary permissions to write to the directory where the file resides. You can check permissions using `ls -l` on the directory and adjust them with `chmod` and `chown` commands if needed.
- Check for Open Files Limit: Sometimes, the system's limit on the number of files that can be open might be reached. Use the command `ulimit -a` to check the current limits and `ulimit -n [new limit]` to increase the number of open files allowed, if necessary.
- Review MySQL Error Log: The MySQL error log can provide specific details about the cause of the error. Locate and review the error log, typically found in `/var/log/mysql/error.log` or specified in the MySQL configuration file (`my.cnf` or `my.ini`), for any detailed error messages related to the failed operation.
- Check InnoDB Status (if applicable): If you are using InnoDB tables, execute `SHOW ENGINE INNODB STATUS;` from the MySQL command line. This can provide insights into any InnoDB related issues that might be causing the error.
- Verify MySQL Server Status: Ensure that the MySQL server is running properly by executing `systemctl status mysql` or `service mysql status` depending on your system's init system.
These steps are targeted actions that a user can take immediately to identify and potentially resolve the "1137: Error writing file" error in MySQL.