You are using an existing server with a new configuration.

The error log shows that the MySQL server failed to start because the size of the ib_logfile0 file on disk (52428800 bytes) does not match the size specified in the configuration file (26214400 bytes). This can happen when the innodb_log_file_size variable is changed without following the proper steps1. The ib_logfile0 and ib_logfile1 files are the InnoDB redo log files, which store the changes made to the InnoDB data before they are written to the data files2. To resolve this issue, you need to remove the existing redo log files and let the server create new ones with the correct size. To do this, you need to:

Stop the MySQL server and make sure that it shuts down without errors.

Delete or rename the ib_logfile0 and ib_logfile1 files from the data directory.

Start the MySQL server again. It will create new redo log files with the size specified in the configuration file.

Note that deleting the redo log files can cause data loss if there are any uncommitted transactions or changes that have not been flushed to the data files. Therefore, it is recommended to backup the data before performing this operation1.