you have just made a change in the configuration file and trying to restart mysql but terminal is showing "failed to start". Now, if you will try to run the mysql console then it will show you the error regarding "can't find the socket" and this is obvious because the mysqld is not running in the back ground.
To know what's happening with your mysql you can go to "mysql-error.log" that is residing mainly in the data-directory of your mysql-server.
suppose you've encountered the error as follows:
InnoDB: Error: log file ./ib_logfile0 is of different size 0 5242880 bytes
InnoDB: than specified in the .cnf file 0 134217728 bytes!
what it is trying to say is that "you have changed a new variable but the file corresponding to that variable in the data directory is not meeting to the specified requirement because it is somewhat smaller in size than that of the one defined in the configuration file".
now you've got the problem and thinking how to increase the size of that file that is in the data-directory then there is no need to do that because ib_logfile0 is the system generated file that would be generated automatically when you start the mysql. So, what you have to do is remove the file that is being generated previously and try to start the mysql.
WHAT!!
still not starting!!!
now you have to go to the mysql-error.log and i know what is creating the problem:
InnoDB: Error: log file ./ib_logfile1 is of different size 0 5242880 bytes
InnoDB: than specified in the .cnf file 0 134217728 bytes!
this is the same file as that of the previous one and what you have to do is to delete it as you'd done before.
now try to restart mysql it will work.
now go to the data-directory and you will find the ib_logfile0 and
ib_logfile1 there.
To know what's happening with your mysql you can go to "mysql-error.log" that is residing mainly in the data-directory of your mysql-server.
suppose you've encountered the error as follows:
InnoDB: Error: log file ./ib_logfile0 is of different size 0 5242880 bytes
InnoDB: than specified in the .cnf file 0 134217728 bytes!
what it is trying to say is that "you have changed a new variable but the file corresponding to that variable in the data directory is not meeting to the specified requirement because it is somewhat smaller in size than that of the one defined in the configuration file".
now you've got the problem and thinking how to increase the size of that file that is in the data-directory then there is no need to do that because ib_logfile0 is the system generated file that would be generated automatically when you start the mysql. So, what you have to do is remove the file that is being generated previously and try to start the mysql.
WHAT!!
still not starting!!!
now you have to go to the mysql-error.log and i know what is creating the problem:
InnoDB: Error: log file ./ib_logfile1 is of different size 0 5242880 bytes
InnoDB: than specified in the .cnf file 0 134217728 bytes!
this is the same file as that of the previous one and what you have to do is to delete it as you'd done before.
now try to restart mysql it will work.
now go to the data-directory and you will find the ib_logfile0 and
ib_logfile1 there.