Ubuntu Server 20.04 2nd Upgrade 성공

패키지 업데이트
패키지를 최신 버전으로 업데이트합니다.
$ sudo apt update && sudo apt upgrade && sudo apt dist-upgrade

업데이트 완료 후 재부팅합니다.
$ sudo reboot now

더 이상 필요하지 않은 패키지를 삭제합니다.
$ sudo apt autoremove && sudo apt clean

업데이트 매니저 설치
update-manager-core가 설치되지 않은 경우 설치합니다.
$ sudo apt install update-manager-core

lts 릴리스로 업데이트 하기 위해 update-manager의 설정을 변경합니다.
$ sudo nano /etc/update-manager/release-upgrades

아래 내용과 같이 Prompt=lts로 변경합니다.
Default behavior for the release upgrader.
[DEFAULT]
# Default prompting behavior, valid options:
#
# never - Never check for, or allow upgrading to, a new release.
# normal - Check to see if a new release is available. If more than one new
# release is found, the release upgrader will attempt to upgrade to
# the supported release that immediately succeeds the
# currently-running release.
# lts - Check to see if a new LTS release is available. The upgrader
# will attempt to upgrade to the first LTS release available after
# the currently-running one. Note that if this option is used and
# the currently-running release is not itself an LTS release the
# upgrader will assume prompt was meant to be normal.
Prompt=lts
Ctrl+X – Y – Enter 하여 저장합니다.

우분투 릴리스 업그레이드
업그레이드를 진행합니다.
$ sudo do-release-upgrade

Get:1169 http://ports.ubuntu.com/ubuntu-ports focal/main armhf vsftpd armhf 3.0.3-12 [103 kB]
Fetched 855 MB in 6s (2,718 kB/s)

Configuring libc6

There are services installed on your system which need to be restarted when certain libraries, such as libpam, libc, and libssl, are upgraded. Since these restarts may cause interruptions of service for the system, you will normally beprompted on each upgrade for the list of services you wish to restart. You can choose this option to avoid being prompted; instead, all necessary restarts will be done for you automatically so you can avoid being asked questions on each library upgrade.
Restart services during package upgrades without asking?

Yes

***************************

Default (Keep~)
A new version (/run/samba/upgrades/smb.conf) of configuration file /etc/samba/smb.conf is available, but the version installed currently has been locally modified.
Default (Keep~)
Configuration file '/etc/redis/redis.conf'
N (Keep~ )
Configuration file '/etc/mysql/mariadb.conf.d/50-server.cnf'
N (Keep~ )
202 packages are going to be removed. 3 new packages are going to be installed.

Fetching and installing the upgrade can take several hours. Once the
download has finished, the process cannot be canceled.

Continue [yN] Details [d] Y
System upgrade is complete.

Restart required

To finish the upgrade, a restart is required.
If you select 'y' the system will be restarted.

Continue [yN] Y
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wordpress php update
sudo a2dismod php7.4

sudo a2enmod php8.0

sudo service apache2 restart