Mysql启动失败：InnoDB: mmap(137428992 bytes) failed; errno 12

快乐描述一下

最近多手升级了一下mysql，结果出现了一下错误，要不是出错了都不会有这篇文章

解决过程

2024-05-12 15:02:43+08:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 5.7.44-1.el7 started.
2024-05-12 15:02:43+08:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'
2024-05-12 15:02:43+08:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 5.7.44-1.el7 started.
'/var/lib/mysql/mysql.sock' -> '/var/run/mysqld/mysqld.sock'
2024-05-12T07:02:44.639921Z 0 [Note] mysqld (mysqld 5.7.44) starting as process 1 ...
2024-05-12T07:02:44.809605Z 0 [Note] InnoDB: PUNCH HOLE support available
2024-05-12T07:02:44.809708Z 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2024-05-12T07:02:44.809721Z 0 [Note] InnoDB: Uses event mutexes
2024-05-12T07:02:44.809725Z 0 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier
2024-05-12T07:02:44.809728Z 0 [Note] InnoDB: Compressed tables use zlib 1.2.13
2024-05-12T07:02:44.809731Z 0 [Note] InnoDB: Using Linux native AIO
2024-05-12T07:02:44.810330Z 0 [Note] InnoDB: Number of pools: 1
2024-05-12T07:02:44.810588Z 0 [Note] InnoDB: Using CPU crc32 instructions
2024-05-12T07:02:44.813686Z 0 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances = 1, chunk size = 128M
2024-05-12T07:02:44.814594Z 0 [ERROR] InnoDB: mmap(137428992 bytes) failed; errno 12
2024-05-12T07:02:44.814618Z 0 [ERROR] InnoDB: Cannot allocate memory for the buffer pool
2024-05-12T07:02:44.814629Z 0 [ERROR] InnoDB: Plugin initialization aborted with error Generic error
2024-05-12T07:02:44.814638Z 0 [ERROR] Plugin 'InnoDB' init function returned error.
2024-05-12T07:02:44.814643Z 0 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
2024-05-12T07:02:44.814648Z 0 [ERROR] Failed to initialize builtin plugins.
2024-05-12T07:02:44.814651Z 0 [ERROR] Aborting

2024-05-12T07:02:44.814667Z 0 [Note] Binlog end
2024-05-12T07:02:44.815119Z 0 [Note] Shutting down plugin 'CSV'
2024-05-12T07:02:44.816517Z 0 [Note] mysqld: Shutdown complete


2024-05-12 15:06:12+08:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 5.7.44-1.el7 started.
2024-05-12 15:06:12+08:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'
2024-05-12 15:06:12+08:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 5.7.44-1.el7 started.
'/var/lib/mysql/mysql.sock' -> '/var/run/mysqld/mysqld.sock'
2024-05-12T07:06:13.479933Z 0 [Note] mysqld (mysqld 5.7.44) starting as process 1 ...
2024-05-12T07:06:13.514431Z 0 [Note] InnoDB: PUNCH HOLE support available
2024-05-12T07:06:13.514483Z 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2024-05-12T07:06:13.514488Z 0 [Note] InnoDB: Uses event mutexes
2024-05-12T07:06:13.514494Z 0 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier
2024-05-12T07:06:13.514497Z 0 [Note] InnoDB: Compressed tables use zlib 1.2.13
2024-05-12T07:06:13.514500Z 0 [Note] InnoDB: Using Linux native AIO
2024-05-12T07:06:13.514924Z 0 [Note] InnoDB: Number of pools: 1
2024-05-12T07:06:13.515214Z 0 [Note] InnoDB: Using CPU crc32 instructions
2024-05-12T07:06:13.528685Z 0 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances = 1, chunk size = 128M
2024-05-12T07:06:13.528788Z 0 [ERROR] InnoDB: mmap(137428992 bytes) failed; errno 12
2024-05-12T07:06:13.528801Z 0 [ERROR] InnoDB: Cannot allocate memory for the buffer pool
2024-05-12T07:06:13.528808Z 0 [ERROR] InnoDB: Plugin initialization aborted with error Generic error
2024-05-12T07:06:13.528822Z 0 [ERROR] Plugin 'InnoDB' init function returned error.
2024-05-12T07:06:13.528827Z 0 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
2024-05-12T07:06:13.531984Z 0 [ERROR] Failed to initialize builtin plugins.
2024-05-12T07:06:13.532007Z 0 [ERROR] Aborting

2024-05-12T07:06:13.532026Z 0 [Note] Binlog end
2024-05-12T07:06:13.535622Z 0 [Note] Shutting down plugin 'CSV'
2024-05-12T07:06:13.537283Z 0 [Note] mysqld: Shutdown complete


根据这些错误信息在网上，大多都是要你修改my.cnf配置文件，我都不知道修改了多少遍了！！！！如修改innodb_buffer_pool_size的大小之类的，但是都没有作用。后面复制整段错误信息查找，找到了正确的解决方法。free指令查看内存：

如果没有设置swap的话，则会显示

[root@VM_0_7_centos /]# free
              total        used      free      shared  buff/cache   available
Mem:        1016516      722544       70124      108428      223848       37380
Swap:             0           0           0

服务器没有配置Swap分区，关于Swap分区可以参见百度百科 (Swap分区) ,知道了当前问题的源头就给机器配置一个Swap分区大小1G，关于设置Swap分区大小可以参考 linux SWAP大小与内存的关系

[root@RainYun-rXQaeJGL ~]# sudo dd if=/dev/zero of=/swapfile bs=1M count=1024
记录了1024+0 的读入
记录了1024+0 的写出
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 1.72224 s, 623 MB/s
[root@RainYun-rXQaeJGL ~]# sudo mkswap /swapfile
mkswap: /swapfile：不安全的权限 0644，建议使用 0600。
正在设置交换空间版本 1，大小 = 1024 MiB (1073737728  个字节)
无标签，UUID=cdf83bfb-810d-4f54-ba58-553096424346
[root@RainYun-rXQaeJGL ~]# sudo swapon /swapfile
swapon: /swapfile：不安全的权限 0644，建议使用 0600。

解决方法

详细报错如下

InnoDB: mmap(137363456 bytes) failed; errno 12
2019-03-13 09:06:25 79498 [ERROR] InnoDB: Cannot allocate memory for the buffer pool
2019-03-13 09:06:25 79498 [ERROR] Plugin 'InnoDB' init function returned error.
2019-03-13 09:06:25 79498 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
2019-03-13 09:06:25 79498 [ERROR] Unknown/unsupported storage engine: InnoDB
2019-03-13 09:06:25 79498 [ERROR] Aborting

解决方法如下：

查看内存

$ free
             total       used       free     shared    buffers     cached
Mem:        608476     565044      43432          0       1284      53996
-/+ buffers/cache:     509764      98712
Swap:            0          0          0

明显的swap问题。适当增加swap

$ sudo dd if=/dev/zero of=/swapfile bs=1M count=1024 #增加1G的SWAP进去
$ sudo mkswap /swapfile
$ sudo swapon /swapfile
$ free
             total       used       free     shared    buffers     cached
Mem:        608476     601432       7044          0        824      88752
-/+ buffers/cache:     511856      96620
Swap:      1048572          0    1048572

然后启动完美解决

## 感谢一下信息来源

https://blog.csdn.net/phpBin/article/details/95166610
感谢这篇文章：https://www.cnblogs.com/olinux/p/5144205.html
及原创文章：https://www.cnblogs.com/olinux/p/5144205.html