Dnf已经在Fedora中,这是Rhel / centos的试验台,但为什么centos 7还在使用yum？

解决方法:

CentOS 7对应于2014年6月发布的Red Hat Enterprise Linux 7.Dnf在2015年11月发布的Fedora 23中取代了yum.没有规定对这样的版本进行根本性更改.在发布中进行的更改是增量的,可能是添加功能,但从不删除现有功能并由其他功能替换它们.

未来版本的CentOS可能会有dnf,除非Red Hat在Red Hat发布版本8时选择其他工具,等等.

进一步阅读：

> Life Cycle and Update Policies(红帽)
> Red Hat Enterprise Linux Life Cycle

During the three-year Production Phase, qualified Critical and Important Security errata advisories (RHSAs) and Urgent and Selected High Priority Bug Fix errata advisories (RHBAs) may be released, as an update to the Red Hat Enterprise Linux Atomic Host image,as they become available. Other errata advisories may be delivered as appropriate.

If available, new or improved hardware enablement and select enhanced software functionality may be provided at the discretion of Red Hat, as an updated image. Updated Red Hat Enterprise Linux Atomic Host images are cumulative and include the contents of previously released updates.

The Red Hat Enterprise Linux life cycle phases are designed to reduce the level of change within each major releasei over time and make release availability and content more predictable.ii

> 1. What is CentOS Linux?(FAQ)

CentOS conforms fully with Red Hat, Inc’s redistribution policies and aims to be functionally compatible with Red Hat Enterprise Linux. CentOS mainly changes packages to remove trademarked vendor branding and artwork.