ubuntu16.04升级到18.04,ubuntu emergency 修复

~# cat /etc/issueUbuntu 18.04.5 LTS n l # apt updateIgn:1 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic InReleaseIgn:2 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates InReleaseIgn:3 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-backports InReleaseIgn:4 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security InReleaseErr:5 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic Release Certificate verification failed: The certificate is NOT trusted. The certificate chain uses expired certificate. Could not handshake: Error in the certificate verification. [IP: 101.6.15.130 443]Err:6 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates Release Certificate verification failed: The certificate is NOT trusted. The certificate chain uses expired certificate. Could not handshake: Error in the certificate verification. [IP: 101.6.15.130 443]Err:7 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-backports Release Certificate verification failed: The certificate is NOT trusted. The certificate chain uses expired certificate. Could not handshake: Error in the certificate verification. [IP: 101.6.15.130 443]Err:8 https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security Release Certificate verification failed: The certificate is NOT trusted. The certificate chain uses expired certificate. Could not handshake: Error in the certificate verification. [IP: 101.6.15.130 443]Reading package lists... DoneE: The repository 'https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic Release' no longer has a Release file.N: Updating from such a repository can't be done securely, and is therefore disabled by default.N: See apt-secure(8) manpage for repository creation and user configuration details.E: The repository 'https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates Release' no longer has a Release file.N: Updating from such a repository can't be done securely, and is therefore disabled by default.N: See apt-secure(8) manpage for repository creation and user configuration details.E: The repository 'https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-backports Release' no longer has a Release file.N: Updating from such a repository can't be done securely, and is therefore disabled by default.N: See apt-secure(8) manpage for repository creation and user configuration details.E: The repository 'https://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security Release' no longer has a Release file.N: Updating from such a repository can't be done securely, and is therefore disabled by default.N: See apt-secure(8) manpage for repository creation and user configuration details. https 替换为 http # cat /etc/apt/sources.list# 默认注释了源码镜像以提高 apt update 速度，如有需要可自行取消注释deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiversedeb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiversedeb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiversedeb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse# 预发布软件源，不建议启用# deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse # apt updateHit:1 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic InReleaseGet:2 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates InRelease [88.7 kB]Get:3 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-backports InRelease [74.6 kB]Get:4 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security InRelease [88.7 kB]Get:5 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/main amd64 Packages [2,303 kB]Get:6 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/main Translation-en [445 kB]Get:7 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/restricted amd64 Packages [540 kB]Get:8 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/restricted Translation-en [73.6 kB]Get:9 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/universe amd64 Packages [1,764 kB]Get:10 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/universe Translation-en [380 kB]Get:11 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/multiverse amd64 Packages [27.3 kB]Get:12 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-updates/multiverse Translation-en [6,808 B]Get:13 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/main amd64 Packages [1,958 kB]Get:14 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/main Translation-en [352 kB]Get:15 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/restricted amd64 Packages [516 kB]Get:16 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/restricted Translation-en [69.9 kB]Get:17 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/universe amd64 Packages [1,148 kB]Get:18 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/universe Translation-en [263 kB]Get:19 http://mirrors.tuna.tsinghua.edu.cn/ubuntu bionic-security/multiverse amd64 Packages [20.9 kB]Fetched 10.1 MB in 7s (1,372 kB/s)Reading package lists... DoneBuilding dependency treeReading state information... Done177 packages can be upgraded. Run 'apt list --upgradable' to see them. 参考 ubuntu更新源报错Certificate verification failed: The certificate is NOT trusted.