Linux set virtual memory (swap) to troubleshoot MySQL hangs due to insufficient memory

The MySQL error log shows:

Innodb:mmap (137363456 bytes) failed; errno 12
2016-03-01 01:38:42 13064 [ERROR] Innodb:cannot allocate memory for the buffer pool
2016-03-01 01:38:42 13064 [ERROR] Plugin ' InnoDB ' init function returned ERROR.
2016-03-01 01:38:42 13064 [ERROR] Plugin ' InnoDB ' registration as a STORAGE ENGINE failed.
2016-03-01 01:38:42 13064 [ERROR] unknown/unsupported storage Engine:innodb
2016-03-01 01:38:42 13064 [ERROR] Aborting

This is usually caused by low system memory, the solution is to upgrade the system memory or add swap;

Workaround:
1) Add the following sentence to the/ETC/MYSQL/MY.CNF mysqld:

innodb_buffer_pool_size = 64M

Also set the swap partition, because my VPS is no swap partition, through fdisk -l and 1mount do not see the swap information, need to manually add.

2) steps to add a swap partition:

2.1) dd if=/dev/zero of=/swapfile bs=1M count=10242.2) mkswap /swapfile2.3) swapon /swapfile2.4) 添加这行： /swapfile swap swap defaults 0 0 到 /etc/fstab

Now that you have set up the swap partition and restarted MySQL, look for a follow-up check to see if it will happen.

Linux set virtual memory (swap) to troubleshoot MySQL hangs due to insufficient memory