自己的ubuntu的sql server 2019莫名的挂了，

检查sql server状态

sudo systemctl status mssql-server

发现sql server挂了

1.查看启用异常信息

journalctl -u mssql-server

2.发现日志种有这么一行

Unable to read instance id from /var/opt/mssql/.system/instance_id

3.google搜索解决方案，链接如下：

https://social.technet.microsoft.com/Forums/en-US/32c2b50b-4000-4ddf-bd7a-6876ca22a213/problem-starting-mssql-service-on-linux?forum=sqlsetupandupgrade

 1.重启sql server

sudo systemctl restart mssql-server