Delta RPMs disabled because /usr/bin/applydeltarpm not installed.

解决办法

此问题安装Deltarpm包（增量 RPM 套件）即可解决，当然您也可以先使用一下命令，查看是哪个包提供applydeltarpm

yum provides ‘*/applydeltarpm‘  
yum install deltarpm -y

yum provides ‘*/applydeltarpm‘
Loaded plugins: axelget, fastestmirror
No metadata available for base
No metadata available for epel
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Loading mirror speeds from cached hostfile
 * epel: mirrors.aliyun.com
base/7/x86_64/filelists_db                                                  | 6.9 MB  00:00:00     
epel/x86_64/filelists                                                       |  10 MB  00:00:00     
extras/7/x86_64/filelists_db                                                | 603 kB  00:00:00     
updates/7/x86_64/filelists_db                                               | 3.4 MB  00:00:00     
deltarpm-3.6-3.el7.x86_64 : Create deltas between rpms
Repo        : base
Matched from:
Filename    : /usr/bin/applydeltarpm

然后安装deltarpm

# yum install deltarpm -y

...
Installed size: 209 k
Downloading packages:
deltarpm-3.6-3.el7.x86_64.rpm                                               |  82 kB  00:00:00     
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
  Installing : deltarpm-3.6-3.el7.x86_64                                                       1/1 
  Verifying  : deltarpm-3.6-3.el7.x86_64                                                       1/1 

Installed:
  deltarpm.x86_64 0:3.6-3.el7                                                                      

Complete!

继续yum updagate即可

/usr/bin/applydeltarpm not installed问题解决