云主机使用了Ubuntu server 20.04 lts minimal镜像, 系统提示新的lts版本发布了, 可以使用do-release-upgrade升级. 然而升级过程中报出了如下错误:

After updating your package information, the essential package 'ubuntu-minimal' could not be located. This may be because you have no official mirrors listed in your software sources, or because of excessive load on the mirror you are using. See /etc/apt/sources.list for the current list of configured software sources. In the case of an overloaded mirror, you may want to try the upgrade again later.

这是由于腾讯云官方给的系统镜像命名和Ubuntu官方源不一致造成的. 解决方法是在运行do-release-upgrade命令之后, 在提示"Press ENTER to continue"时打开一个新的终端, 修改/etc/apt/source.list, 将apt源里的腾讯云镜像站给取消注释, 使其生效. 此时再按下ENTER继续后将可正常更新了.

PS: 此外也可以试试这个命令 sudo do-release-upgrade --allow-third-party .

参考: Cannot update to 19.04 -the essential package 'ubuntu-minimal' could not be located. | DigitalOcean