解决yum按照软件提示Could not resolve host: mirror.webtatic.com; Unknown error的错误

 yum -y install php71w php71w-cli php71w-common php71w-devel php71w-embedded php71w-gd php71w-mcrypt php71w-mbstring php71w-pdo php71w-xml php71w-fpm php71w-mysqlnd php71w-opcache php71w-pecl-memcached php71w-pecl-redis php71w-
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Could not retrieve mirrorlist https://mirror.webtatic.com/yum/el7/x86_64/mirrorlist error was
14: curl#6 - "Could not resolve host: mirror.webtatic.com; Unknown error"


One of the configured repositories failed (Unknown),
and yum doesn't have enough cached data to continue. At this point the only
safe thing yum can do is fail. There are a few ways to work "fix" this:

1. Contact the upstream for the repository and get them to fix the problem.

2. Reconfigure the baseurl/etc. for the repository, to point to a working
upstream. This is most often useful if you are using a newer
distribution release than is supported by the repository (and the
packages for the previous distribution release still work).

3. Run the command with the repository temporarily disabled
yum --disablerepo= ...

4. Disable the repository permanently, so yum won't use it by default. Yum
will then just ignore the repository until you permanently enable it
again or use --enablerepo for temporary usage:

yum-config-manager --disable 
or
subscription-manager repos --disable=

5. Configure the failing repository to be skipped, if it is unavailable.
Note that yum will try to contact the repo. when it runs most commands,
so will have to try and fail each time (and thus. yum will be be much
slower). If it is a very temporary problem though, this is often a nice
compromise:

yum-config-manager --save --setopt=.skip_if_unavailable=true

Cannot find a valid baseurl for repo: webtatic/x86_64


One of the configured repositories failed (Unknown),
and yum doesn't have enough cached data to continue. At this point the only
safe thing yum can do is fail. There are a few ways to work "fix" this:

1. Contact the upstream for the repository and get them to fix the problem.

2. Reconfigure the baseurl/etc. for the repository, to point to a working
upstream. This is most often useful if you are using a newer
distribution release than is supported by the repository (and the
packages for the previous distribution release still work).

3. Run the command with the repository temporarily disabled
yum --disablerepo= ...

4. Disable the repository permanently, so yum won't use it by default. Yum
will then just ignore the repository until you permanently enable it
again or use --enablerepo for temporary usage:

yum-config-manager --disable 
or
subscription-manager repos --disable=

5. Configure the failing repository to be skipped, if it is unavailable.
Note that yum will try to contact the repo. when it runs most commands,
so will have to try and fail each time (and thus. yum will be be much
slower). If it is a very temporary problem though, this is often a nice
compromise:

yum-config-manager --save --setopt=.skip_if_unavailable=true

如果使用 yum list 或者安装某文件时提示这种报错，host 解析有问题，请检查网络 DNS 设置，重启网络服务，OK。

webtatic 源无法访问导致yum无法使用

14: curl#6 - "Could not resolve host: mirror.webtatic.com; Unknown error"

无法解析主机（域名）

解决：

打开网站https://mirror.webtatic.com/yum/el7/x86_64/mirrorlist
会看到两个文件
内容：
https://uk.repo.webtatic.com/yum/el7/x86_64/
https://us-east.repo.webtatic.com/yum/el7/x86_64

这是两个国家的源下载速度都不快

修改/etc/yum.repos.d/webtatic.repo

baseurl=https://us-east.repo.webtatic.com/yum/el7/x86_64

@安装php

把源 关闭

gzip /etc/yum.repos.d/webtatic.repo