[Errno 256] No more mirrors to try.错误的解决方式

在centOS 7系统上搭建FTP服务器时，在执行第一步安装命令时便报以下错误：

[root@localhost ~]# yum -y install vsftpd
已加载插件：fastestmirror
Loading mirror speeds from cached hostfile
 * base: mirrors.zju.edu.cn
 * extras: mirrors.zju.edu.cn
 * updates: mirrors.zju.edu.cn
正在解决依赖关系
--> 正在检查事务
---> 软件包 vsftpd.x86_64.0.3.0.2-22.el7 将被 安装
--> 解决依赖关系完成

依赖关系解决

================================================================================
 Package          架构             版本                    源              大小
================================================================================
正在安装:
 vsftpd           x86_64           3.0.2-22.el7            base           169 k

事务概要
================================================================================
安装  1 软件包

总下载量：169 k
安装大小：348 k
Downloading packages:
vsftpd-3.0.2-22.el7.x86_64.rpm FAILED
http://mirrors.cqu.edu.cn/CentOS/7.4.1708/os/x86_64/Packages/vsftpd-3.0.2-22.el7.x86_64.rpm: [Errno 14] curl#6 - "Could not resolve host: mirrors.cqu.edu.cn; Unknown error"
正在尝试其它镜像。
vsftpd-3.0.2-22.el7.x86_64.rpm FAILED
http://mirrors.shu.edu.cn/centos/7.4.1708/os/x86_64/Packages/vsftpd-3.0.2-22.el7.x86_64.rpm: [Errno 14] curl#6 - "Could not resolve host: mirrors.shu.edu.cn; Unknown error"
正在尝试其它镜像。
vsftpd-3.0.2-22.el7.x86_64.rpm FAILED
http://mirrors.aliyun.com/centos/7.4.1708/os/x86_64/Packages/vsftpd-3.0.2-22.el7.x86_64.rpm: [Errno 14] curl#6 - "Could not resolve host: mirrors.aliyun.com; Unknown error"
正在尝试其它镜像。
vsftpd-3.0.2-22.el7.x86_64.rpm FAILED
http://mirror.bit.edu.cn/centos/7.4.1708/os/x86_64/Packages/vsftpd-3.0.2-22.el7.x86_64.rpm: [Errno 14] curl#6 - "Could not resolve host: mirror.bit.edu.cn; Unknown error"
正在尝试其它镜像。
vsftpd-3.0.2-22.el7.x86_64.rpm FAILED
http://mirrors.neusoft.edu.cn/centos/7.4.1708/os/x86_64/Packages/vsftpd-3.0.2-22.el7.x86_64.rpm: [Errno 14] curl#6 - "Could not resolve host: mirrors.neusoft.edu.cn; Unknown error"
正在尝试其它镜像。
vsftpd-3.0.2-22.el7.x86_64.rpm FAILED
http://mirrors.tuna.tsinghua.edu.cn/centos/7.4.1708/os/x86_64/Packages/vsftpd-3.0.2-22.el7.x86_64.rpm: [Errno 14] curl#6 - "Could not resolve host: mirrors.tuna.tsinghua.edu.cn; Unknown error"
正在尝试其它镜像。
vsftpd-3.0.2-22.el7.x86_64.rpm FAILED
http://mirrors.nwsuaf.edu.cn/centos/7.4.1708/os/x86_64/Packages/vsftpd-3.0.2-22.el7.x86_64.rpm: [Errno 14] curl#6 - "Could not resolve host: mirrors.nwsuaf.edu.cn; Unknown error"
正在尝试其它镜像。
vsftpd-3.0.2-22.el7.x86_64.rpm FAILED
http://mirrors.zju.edu.cn/centos/7.4.1708/os/x86_64/Packages/vsftpd-3.0.2-22.el7.x86_64.rpm: [Errno 14] curl#6 - "Could not resolve host: mirrors.zju.edu.cn; Unknown error"
正在尝试其它镜像。
vsftpd-3.0.2-22.el7.x86_64.rpm FAILED
http://mirrors.sohu.com/centos/7.4.1708/os/x86_64/Packages/vsftpd-3.0.2-22.el7.x86_64.rpm: [Errno 14] curl#6 - "Could not resolve host: mirrors.sohu.com; Unknown error"
正在尝试其它镜像。
vsftpd-3.0.2-22.el7.x86_64.rpm FAILED
http://mirror.lzu.edu.cn/centos/7.4.1708/os/x86_64/Packages/vsftpd-3.0.2-22.el7.x86_64.rpm: [Errno 14] curl#6 - "Could not resolve host: mirror.lzu.edu.cn; Unknown error"
正在尝试其它镜像。


Error downloading packages:
  vsftpd-3.0.2-22.el7.x86_64: [Errno 256] No more mirrors to try.

[root@localhost ~]#

解决方式：

1、yum clean all
2、yum makecache

[root@localhost ~]# yum clean all
已加载插件：fastestmirror
正在清理软件源： base extras updates
Cleaning up everything
[root@localhost ~]# yum makecache
已加载插件：fastestmirror
base                                                     | 3.6 kB     00:00
extras                                                   | 3.4 kB     00:00
updates                                                  | 3.4 kB     00:00
(1/12): base/7/x86_64/group_gz                             | 166 kB   00:00
(2/12): extras/7/x86_64/filelists_db                       | 603 kB   00:02
(3/12): extras/7/x86_64/prestodelta                        | 100 kB   00:02
(4/12): extras/7/x86_64/primary_db                         | 205 kB   00:00
(5/12): extras/7/x86_64/other_db                           | 126 kB   00:00
(6/12): base/7/x86_64/filelists_db                         | 6.9 MB   00:07
(7/12): updates/7/x86_64/filelists_db                      | 3.4 MB   00:05
(8/12): updates/7/x86_64/other_db                          | 578 kB   00:02
(9/12): base/7/x86_64/primary_db                           | 5.9 MB   00:12
(10/12): updates/7/x86_64/primary_db                       | 6.0 MB   00:05
(11/12): base/7/x86_64/other_db                            | 2.5 MB   00:15
updates/7/x86_64/prestodelta   FAILED
http://mirrors.njupt.edu.cn/centos/7.5.1804/updates/x86_64/repodata/8ee07a5e1fde5231fed8ce55547405923af529a0902e57aeee1676035ae7a367-prestodelta.xml.gz: [Errno 12] Timeout on http://10.10.254.10/cache/2/02/mirrors.njupt.edu.cn/a8bc5955244fcfe9599025498ceada44/8ee07a5e1fde5231fed8ce55547405923af529a0902e57aeee1676035ae7a367-prestodelta.xml.gz: (28, 'Connection timed out after 31022 milliseconds')
正在尝试其它镜像。
(12/12): updates/7/x86_64/prestodelta                      | 679 kB   00:00
Determining fastest mirrors
 * base: mirrors.nwsuaf.edu.cn
 * extras: centos.ustc.edu.cn
 * updates: mirror.lzu.edu.cn
元数据缓存已建立

3.完了也可以再给yum来个升级【可选】。

yum -y update

 

然后重新安装就ok。