MySql service won't start from recovered ibdata1 file - mysql

Question

One of our servers was the subject of a ransomware attack from a group of international Hackers. So we’ve re-grouped and started over and the only unaffected data we had was the ibdata1 file stored in mysql program data folder.
We would like to restore that data on the new instance so that we carry forward our operations but after trying to run the new installation of mysql it the service stops with error 1067. It suggests to delete all files created by InnoDB: all ibdata files and all ib_logfile files. If I do that the service will run but I can’t do it because I need to access the data in this particular data file. I’ve also added these two lines in my .cnf file
innodb_force_recovery=6
innodb_fast_shutdown=0
That hasn’t worked. So I deleted just the log files and it created new log files along with it came this error
190223 11:38:48 [Note] Plugin 'FEDERATED' is disabled.
190223 11:38:48 InnoDB: The InnoDB memory heap is disabled
190223 11:38:48 InnoDB: Mutexes and rw_locks use Windows interlocked functions
190223 11:38:48 InnoDB: Compressed tables use zlib 1.2.3
190223 11:38:48 InnoDB: Initializing buffer pool, size = 2.0G
190223 11:38:48 InnoDB: Completed initialization of buffer pool
190223 11:38:48 InnoDB: highest supported file format is Barracuda.
InnoDB: No valid checkpoint found.
InnoDB: If this error appears when you are creating an InnoDB database,
InnoDB: the problem may be that during an earlier attempt you managed
InnoDB: to create the InnoDB data files, but log file creation failed.
InnoDB: If that is the case, please refer to
InnoDB: http://dev.mysql.com/doc/refman/5.5/en/error-creating-innodb.html
190223 11:38:48 [ERROR] Plugin 'InnoDB' init function returned error.
190223 11:38:48 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
190223 11:38:48 [ERROR] Unknown/unsupported storage engine: INNODB
190223 11:38:48 [ERROR] Aborting
Then I replaced the log files with the same ones I used with the original ibdata1 file then I got this error.
190223 12:11:26 [Note] Plugin 'FEDERATED' is disabled.
190223 12:11:26 InnoDB: The InnoDB memory heap is disabled
190223 12:11:26 InnoDB: Mutexes and rw_locks use Windows interlocked functions
190223 12:11:26 InnoDB: Compressed tables use zlib 1.2.3
190223 12:11:26 InnoDB: Initializing buffer pool, size = 2.0G
190223 12:11:26 InnoDB: Completed initialization of buffer pool
InnoDB: Error: log file .\ib_logfile0 is of different size 0 1073741824 bytes
InnoDB: than specified in the .cnf file 0 224395264 bytes!
190223 12:11:26 [ERROR] Plugin 'InnoDB' init function returned error.
190223 12:11:26 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
190223 12:11:26 [ERROR] Unknown/unsupported storage engine: INNODB
190223 12:11:26 [ERROR] Aborting
It appears there is a check point somewhere in the log files that is necessary for the data file to be read properly by the mysql service. Maybe I need to specify the log file size in the my.ini config file. But I don’t know how to go about it.
Any help will really come in handy here.

Answer 1

In your my.ini (or my.cnf) file, add (or replace) the following line:
innodb_log_file_size = 1024M
See https://dev.mysql.com/doc/refman/5.6/en/innodb-parameters.html#sysvar_innodb_log_file_size for details.