報錯：
File "/usr/bin/yum", line 29, in <module>
yummain.user_main(sys.argv[1:], exit_code=True)
File "/usr/share/yum-cli/yummain.py", line 294, in user_main
errcode = main(args)
File "/usr/share/yum-cli/yummain.py", line 146, in main
result, resultmsgs = base.doCommands()
File "/usr/share/yum-cli/cli.py", line 438, in doCommands
return self.yum_cli_commands[self.basecmd].doCommand(self, self.basecmd, self.extcmds)
File "/usr/share/yum-cli/yumcommands.py", line 559, in doCommand
base.repos.doSetup()
File "/usr/lib/python2.6/site-packages/yum/repos.py", line 105, in doSetup
self.ayum.plugins.run('postreposetup')
File "/usr/lib/python2.6/site-packages/yum/plugins.py", line 184, in run
func(conduitcls(self, self.base, conf, **kwargs))
File "/usr/lib/yum-plugins/fastestmirror.py", line 202, in postreposetup_hook
all_urls = FastestMirror(all_urls).get_mirrorlist()
File "/usr/lib/yum-plugins/fastestmirror.py", line 369, in get_mirrorlist
self._poll_mirrors()
File "/usr/lib/yum-plugins/fastestmirror.py", line 413, in _poll_mirrors
pollThread.start()
File "/usr/lib64/python2.6/threading.py", line 474, in start
_start_new_thread(self.__bootstrap, ())
thread.error: can't start new thread解決方案：
在一些廉價VPS上運行Yum時可能會出 現:”thread.error: can’t start new thread”的錯誤， 原因就是因爲內存太小了，以至於導致在尋找最快鏡像的時候內存不足。
發生的原因在於fastestmirror，而禁用fastestmirror就可以解決這個問題，具體的解決辦法是將fastestmirror.conf中的enabled=1改成enabled=0。
在登錄SSH之後，編輯/etc/yum/pluginconf.d/fastestmirror.conf文件，把enabled從其中的把enabled=1改爲enabled=0即可。
執行如下命令一鍵修改：
sed -i ‘s/enabled=1/enabled=0/g’ /etc/yum/pluginconf.d/fastestmirror.conf