重启redis服务时报错：Failed to start redis.service: Unit not found
redis配合安全修改了bind和auth配置，重启的时候报错了，试了很多方法，最后才通过日志解决了
1 重新加载systemd 配置并启动：
sudo systemctl daemon-reload
sudo systemctl start redis
> sudo systemctl daemon-reload
> sudo systemctl start redisFailed to start redis.service: Unit not found.2 查看当前redis状态
sudo systemctl status redis
> sudo systemctl status redis● redis.service - Redis persistent key-value databaseLoaded: loaded (/usr/lib/systemd/system/redis.service; disabled; vendor preset: disabled)Drop-In: /etc/systemd/system/redis.service.d└─limit.confActive: failed (Result: exit-code) since Thu 2024-08-08 18:01:26 CST; 16h agoProcess: 2375 ExecStart=/usr/bin/redis-server /etc/redis.conf --supervised systemd (code=exited, status=1/FAILURE)Main PID: 2375 (code=exited, status=1/FAILURE)Aug 08 18:01:26 yangxiuqing-linux.bcc-bdbl.baidu.com systemd[1]: Starting Redis persistent key-value database...
Aug 08 18:01:26 yangxiuqing-linux.bcc-bdbl.baidu.com systemd[1]: Started Redis persistent key-value database.
Aug 08 18:01:26 yangxiuqing-linux.bcc-bdbl.baidu.com systemd[1]: redis.service: main process exited, code=exited, status=1/FAILURE
Aug 08 18:01:26 yangxiuqing-linux.bcc-bdbl.baidu.com systemd[1]: Unit redis.service entered failed state.
Aug 08 18:01:26 yangxiuqing-linux.bcc-bdbl.baidu.com systemd[1]: redis.service failed.
3 发现是失败的，接着看下日志
cat /var/log/redis/redis.log
> cat /var/log/redis/redis.log25420:C 08 Aug 17:53:45.282 * supervised by systemd, will signal readiness
25420:M 08 Aug 17:53:45.283 # Creating Server TCP listening socket 127.0.0.1:6379: bind: Address already in use
2101:M 08 Aug 18:01:11.325 # Creating Server TCP listening socket 127.0.0.1:6379: bind: Address already in use
2375:C 08 Aug 18:01:26.974 * supervised by systemd, will signal readiness
2375:M 08 Aug 18:01:26.975 # Creating Server TCP listening socket 127.0.0.1:6379: bind: Address already in use
错误信息 “Creating Server TCP listening socket 127.0.0.1:6379: bind: Address already in use” 表明 Redis 试图绑定到本地地址 127.0.0.1:6379，但该端口已经被其他进程占用。可以按照以下步骤来解决这个问题：
> sudo lsof -i :6379COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
redis-ser 2407 root 6u IPv4 391104235 0t0 TCP *:6379 (LISTEN)> sudo kill 2407
杀掉原进程 再次重启并观察状态
> sudo systemctl daemon-reload
> sudo systemctl start redis
> sudo systemctl status redis查看状态
● redis.service - Redis persistent key-value databaseLoaded: loaded (/usr/lib/systemd/system/redis.service; disabled; vendor preset: disabled)Drop-In: /etc/systemd/system/redis.service.d└─limit.confActive: active (running) since Fri 2024-08-09 10:16:07 CST; 8s agoMain PID: 21028 (redis-server)CGroup: /system.slice/redis.service└─21028 /usr/bin/redis-server 127.0.0.1:6379Aug 09 10:16:07 yangxiuqing-linux.bcc-bdbl.baidu.com systemd[1]: Starting Redis persistent key-value database...
Aug 09 10:16:07 yangxiuqing-linux.bcc-bdbl.baidu.com systemd[1]: Started Redis persistent key-value database.
成功了！
在Linux系统中使用nano文本编辑器时，保存文件并退出操作步骤
1 保存：按下 Ctrl + O（即 Control 键和字母O键同时按）
2 确认文件名：如果不需要改变文件名，按 Enter 键确认
3 退出：按下 Ctrl + X（即 Control 键和字母X键同时按）
