先确认，磁盘是否充足

df -h

检查是否因内不足被杀

dmesg -T | grep -i "killed process"

如果看到类似：Out of memory: Kill process 1234 (mysqld) ... 就是内存不足

检查数据库文件是否合理：

sudo vi /etc/my.cnf

以上是小内存合理的配置：

[client] port = 3306 socket = /var/lib/mysql/mysql.sock [mysqld] # 基础设置 port = 3306 socket = /var/lib/mysql/mysql.sock datadir = /home/mysql pid-file = /var/run/mysqld/mysqld.pid log-error = /var/log/mysqld.log # 存储引擎 default_storage_engine = InnoDB # 安全与兼容 skip-external-locking # 内存优化（关键！针对小内存机器） innodb_buffer_pool_size = 128M key_buffer_size = 16M max_connections = 50 max_allowed_packet = 64M # 缓冲区（适度调低） sort_buffer_size = 512K read_buffer_size = 512K read_rnd_buffer_size = 512K join_buffer_size = 512K thread_stack = 256K binlog_cache_size = 32K # 临时表 & 表缓存 tmp_table_size = 32M max_heap_table_size = 32M table_open_cache = 128 # 线程缓存 thread_cache_size = 8 # 禁用 Query Cache（避免问题） query_cache_type = 0 query_cache_size = 0 # 其他 myisam_sort_buffer_size = 8M net_buffer_length = 4K

重启数据库：

sudo systemctl restart mysqld

检查是否启动成：

systemctl status mysqld journalctl -u mysqld -n 30 --no-pager