由于我仅在安装了很少服务的系统上运行,所以在运行preupg后我没有得到实际的结果。甚至在一台装了更多服务的系统上也得到了相同的结果(有许多行,因此只显示部分行作为例子);$ sudo preupgPreupg tool doesn*t do the actual upgrade.Please ensure you have backed up your system and/or data in the event of a failed upgrade that would require a full re-install of the system from installation media.Do you want to continue? y/nyGathering logs used by preupgrade assistant:All installed packages : 01/10 ...finished (time 00:00s)All changed files : 02/10 ...finished (time 00:48s)Changed config files : 03/10 ...finished (time 00:00s)All users : 04/10 ...finished (time 00:00s)...042/100 ...done (samba shared directories selinux)043/100 ...done (CUPS Browsing/BrowsePoll configuration)044/100 ...done (CVS Package Split)...|samba shared directories selinux |notapplicable ||CUPS Browsing/BrowsePoll configuration |notapplicable ||CVS Package Split |notapplicable |...就像上面提到的,Preupgrade Assistant只是帮助分析在更新的时候会出现什么问题-真正的步骤需要用l redhat-upgrade-tool-cli. 工具完成。要让这个工具可以有效工作,必须先导入CentOS 7的键:$ sudo rpm --import
http://isoredirect.centos.org/centos/7/os/x86_64/RPM-GPG-KEY-CentOS-7