当前有主机的操作系统是OpenEuler 20.03-SP3，正好有些空闲时间，于是尝试升级至opneEuler 22.03-SP4，以下为操作步骤。
1. 备份repo
cd /etc/yum.repos.d/
mv openEuler.repo openEuler.repo.bak
2. 创建新repo
vi /etc/yum.repos.d/openEuler-22.03-LTS-SP4.repo
输入以下内容:
[SP4_OS]
name=SP4_OS
baseurl=http://repo.openeuler.org/openEuler-22.03-LTS-SP4/OS/$basearch/
metadata_expire=1h
enabled=1
gpgcheck=1
gpgkey=http://repo.openeuler.org/openEuler-22.03-LTS-SP4/OS/$basearch/RPM-GPG-KEY-openEuler
[SP4_everything]
name=SP4_everything
baseurl=http://repo.openeuler.org/openEuler-22.03-LTS-SP4/everything/$basearch/
metadata_expire=1h
enabled=1
gpgcheck=1
gpgkey=http://repo.openeuler.org/openEuler-22.03-LTS-SP4/everything/$basearch/RPM-GPG-KEY-openEuler
[SP4_EPOL]
name=EPOL
baseurl=http://repo.openeuler.org/openEuler-22.03-LTS-SP4/EPOL/main/$basearch/
metadata_expire=1h
enabled=1
gpgcheck=1
gpgkey=http://repo.openeuler.org/openEuler-22.03-LTS-SP4/OS/$basearch/RPM-GPG-KEY-openEuler
[SP4_debuginfo]
name=debuginfo
baseurl=http://repo.openeuler.org/openEuler-22.03-LTS-SP4/debuginfo/$basearch/
metadata_expire=1h
enabled=1
gpgcheck=1
gpgkey=http://repo.openeuler.org/openEuler-22.03-LTS-SP4/debuginfo/$basearch/RPM-GPG-KEY-openEuler
[SP4_source]
name=source
baseurl=http://repo.openeuler.org/openEuler-22.03-LTS-SP4/source/
metadata_expire=1h
enabled=1
gpgcheck=1
gpgkey=http://repo.openeuler.org/openEuler-22.03-LTS-SP4/source/RPM-GPG-KEY-openEuler
[SP4_update]
name=SP4_update
baseurl=http://repo.openeuler.org/openEuler-22.03-LTS-SP4/update/$basearch/
metadata_expire=1h
enabled=1
gpgcheck=1
gpgkey=http://repo.openeuler.org/openEuler-22.03-LTS-SP4/OS/$basearch/RPM-GPG-KEY-openEuler
[SP4_update-source]
name=SP4_update-source
baseurl=http://repo.openeuler.org/openEuler-22.03-LTS-SP4/update/source/
metadata_expire=1h
enabled=1
gpgcheck=1
gpgkey=http://repo.openeuler.org/openEuler-22.03-LTS-SP4/source/RPM-GPG-KEY-openEuler
3. 执行更新
dnf update --allowerasing |tee update_log
因为是开发环境，所以暴力一些，遇到冲突项就直接移除，待后续有需要再进行安装。现阶段部署基本采用Docker部署，因此依赖冲突项较少.
执行的时候，遇到问题如下所示:
Importing GPG key 0xB675600B:
Userid : "openeuler <openeuler@compass-ci.com>"
Fingerprint: 8AA1 6BF9 F2CA 5244 010D CA96 3B47 7C60 B675 600B
From : http://repo.openeuler.org/openEuler-22.03-LTS-SP4/OS/x86_64/RPM-GPG-KEY-openEuler
Is this ok [y/N]: SP4_update 6.4 kB/s | 3.0 kB 00:00
Importing GPG key 0xB675600B:
Userid : "openeuler <openeuler@compass-ci.com>"
Fingerprint: 8AA1 6BF9 F2CA 5244 010D CA96 3B47 7C60 B675 600B
From : http://repo.openeuler.org/openEuler-22.03-LTS-SP4/OS/x86_64/RPM-GPG-KEY-openEuler
Is this ok [y/N]: y
Key imported successfully
Didn't install any keys
Public key for cairo-gobject-1.17.4-4.oe2203sp4.x86_64.rpm is not installed. Failing package is: cairo-gobject-1.17.4-4.oe2203sp4.x86_64
GPG Keys are configured as: http://repo.openeuler.org/openEuler-22.03-LTS-SP4/OS/x86_64/RPM-GPG-KEY-openEuler
Public key for duktape-2.7.0-1.oe2203sp4.x86_64.rpm is not installed. Failing package is: duktape-2.7.0-1.oe2203sp4.x86_64
GPG Keys are configured as: http://repo.openeuler.org/openEuler-22.03-LTS-SP4/OS/x86_64/RPM-GPG-KEY-openEuler
Public key for gcr-base-3.41.0-3.oe2203sp4.x86_64.rpm is not installed. Failing package is: gcr-base-3.41.0-3.oe2203sp4.x86_64
GPG Keys are configured as: http://repo.openeuler.org/openEuler-22.03-LTS-SP4/OS/x86_64/RPM-GPG-KEY-openEuler
Public key for inih-56-1.oe2203sp4.x86_64.rpm is not installed. Failing package is: inih-56-1.oe2203sp4.x86_64
GPG Keys are configured as: http://repo.openeuler.org/openEuler-22.03-LTS-SP4/OS/x86_64/RPM-GPG-KEY-openEuler
Public key for jitterentropy-library-3.3.1-2.oe2203sp4.x86_64.rpm is not installed. Failing package is: jitterentropy-library-3.3.1-2.oe2203sp4.x86_64
GPG Keys are configured as: http://repo.openeuler.org/openEuler-22.03-LTS-SP4/OS/x86_64/RPM-GPG-KEY-openEuler
Public key for psmisc-23.5-2.oe2203sp4.x86_64.rpm is not installed. Failing package is: psmisc-23.5-2.oe2203sp4.x86_64
GPG Keys are configured as: http://repo.openeuler.org/openEuler-22.03-LTS-SP4/OS/x86_64/RPM-GPG-KEY-openEuler
Public key for tpm2-tss-3.1.0-5.oe2203sp4.x86_64.rpm is not installed. Failing package is: tpm2-tss-3.1.0-5.oe2203sp4.x86_64
GPG Keys are configured as: http://repo.openeuler.org/openEuler-22.03-LTS-SP4/OS/x86_64/RPM-GPG-KEY-openEuler
Public key for userspace-rcu-0.13.0-5.oe2203sp4.x86_64.rpm is not installed. Failing package is: userspace-rcu-0.13.0-5.oe2203sp4.x86_64
GPG Keys are configured as: http://repo.openeuler.org/openEuler-22.03-LTS-SP4/OS/x86_64/RPM-GPG-KEY-openEuler
The downloaded packages were saved in cache until the next successful transaction.
You can remove cached packages by executing 'dnf clean packages'.
Error: GPG check FAILED
解决方案如下所示：
# 下载GPG密钥文件
wget -O /etc/pki/rpm-gpg/RPM-GPG-KEY-openEuler-22.03-SP4 \
https://repo.openeuler.org/openEuler-22.03-LTS-SP4/OS/x86_64/RPM-GPG-KEY-openEuler
# 导入密钥
sudo rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-openEuler-22.03-SP4
# 清除DNF缓存
sudo dnf clean all
sudo rm -rf /var/cache/dnf/*
执行完以上步骤后，重启机器，执行cat /etc/openEuler-latest可发现系统版本已升级。