centos7 spacewalk使用过程中的错误debug

(1) The following packages are not available in any of the channels associated to this kickstart profile: pyOpenSSL, rhnlib, libxml2-python, libxml2, spacewalk-koan*. In order for all kickstart functionality to work correctly, these packages should be present in at least one channel associated to this profile.
这种问题是因为这些包在spacewalk的client端，所有需要将spacewalk-client-2.8的repo import进来。而2.8的client repo，没有具体路径，这里的解决方案是，先在client端，down掉所有的client包，再拷贝到server端完成。

client端：
yum install yum-utils
reposync -r spacewalk-client
scp -r /var/cache/yum/x86_64/7/spacewalk-client/packages/spacewalk-client/* root@135.251.206.15:/var/ftp/pub/spacewalk-client
server端：
repo的url设置成：file:///var/ftp/pub/spacewalk-client

（2） file /usr/bin/cobbler from install of cobbler-2.8.4-4.el7.x86_64 conflicts with file from package cobbler20-2.0.11-78.el7.noarch

/etc/yum.conf里面加上exclude=cobbler-epel.noarch

（3）TFTP. PXE-T01: File not found. PXE-E3B: TFTP Error - File not found

将/usr/share/syslinux里面的pxelinux.0直接拷贝到/var/lib/tftpboot下面即可