Problem: I was restarting my server’s mysql service when I got this issue as mysql stopped successfully but could not start and throwing below error message.
Error Message: server quit without updating PID file (/var/lib/mysql/mysql.pid).[FAILED]
Steps for Resolution:
Step1: I checked my server’s error logs, where I got below error message.
InnoDB: Initializing buffer pool, size = 12.0G
InnoDB: mmap(13186891776 bytes) failed; errno 12
nnoDB: Completed initialization of buffer pool
InnoDB: Fatal error: cannot allocate memory for the buffer pool
Step2: As above error message is indicating that there is no sufficient memory to allocate for buffer pool, so I checked my.cnf file where buffer pool is updated as 32GB while this server has only 6GB RAM.
Special: This RAM mismatch was because we created this server (for some testing) as a sanpshot of another server which was have enough memory (64GB) and forget to change variables according to this server RAM.
Step3: I just changed MEMORY value for different variables in my.cnf file as per my server RAM and start mysql. Now it was successfully started.