내가 실행하면 sudo apt-get update이것이 내가 얻는 것입니다
E: The repository 'http://in.archive.ubuntu.com/ubuntu cosmic Release' does not have 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 'http://in.archive.ubuntu.com/ubuntu cosmic-updates Release' does not have 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 'http://in.archive.ubuntu.com/ubuntu cosmic-backports Release' does not have 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 'http://security.ubuntu.com/ubuntu cosmic-security Release' does not have 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.
W: GPG error: https://dl.bintray.com/apache/cassandra 311x InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F1000962B7F6840C
E: The repository 'http://www.apache.org/dist/cassandra/debian 311x InRelease' is not signed.
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.
W: Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list.d/cassandra.list:1 and /etc/apt/sources.list.d/cassandra.sources.list:1
W: Target Packages (main/binary-i386/Packages) is configured multiple times in /etc/apt/sources.list.d/cassandra.list:1 and /etc/apt/sources.list.d/cassandra.sources.list:1
W: Target Packages (main/binary-all/Packages) is configured multiple times in /etc/apt/sources.list.d/cassandra.list:1 and /etc/apt/sources.list.d/cassandra.sources.list:1
W: Target Translations (main/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list.d/cassandra.list:1 and /etc/apt/sources.list.d/cassandra.sources.list:1
W: Target Translations (main/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list.d/cassandra.list:1 and /etc/apt/sources.list.d/cassandra.sources.list:1
W: Target DEP-11 (main/dep11/Components-amd64.yml) is configured multiple times in /etc/apt/sources.list.d/cassandra.list:1 and /etc/apt/sources.list.d/cassandra.sources.list:1
W: Target DEP-11 (main/dep11/Components-all.yml) is configured multiple times in /etc/apt/sources.list.d/cassandra.list:1 and /etc/apt/sources.list.d/cassandra.sources.list:1
W: Target DEP-11-icons-small (main/dep11/icons-48x48.tar) is configured multiple times in /etc/apt/sources.list.d/cassandra.list:1 and /etc/apt/sources.list.d/cassandra.sources.list:1
W: Target DEP-11-icons (main/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list.d/cassandra.list:1 and /etc/apt/sources.list.d/cassandra.sources.list:1
W: Target CNF (main/cnf/Commands-amd64) is configured multiple times in /etc/apt/sources.list.d/cassandra.list:1 and /etc/apt/sources.list.d/cassandra.sources.list:1
W: Target CNF (main/cnf/Commands-all) is configured multiple times in /etc/apt/sources.list.d/cassandra.list:1 and /etc/apt/sources.list.d/cassandra.sources.list:1
지금은 아무것도 설치할 수 없습니다.
답변1
Ubuntu 18.10(Cosmic Cuttlefish)은 2019년 7월에 수명이 종료되어 Ubuntu 아카이브에서 제거되었습니다. 현재로서는 몇 가지 심각한 보안 문제가 있으므로 가능한 한 빨리 지원되는 버전으로 업그레이드해야 합니다.
안타깝게도 Ubuntu는 LTS가 아닌 버전(예: 18.10)에서 다음 LTS 20.04로의 업그레이드를 지원하지 않으므로 유일한 옵션은 다시 설치하는 것입니다.
거울을 다음으로 교체하면 얻을 수 있습니다.
http://old-releases.ubuntu.com/ubuntu/
이를 통해 18.10→19.04→19.10→20.04로 점진적으로 업그레이드하여 최종적으로 지원되는 LTS 릴리스에 도달할 수 있습니다. 하지만 다시 설치하는 것이 더 빠르게 들립니다.