之前阿里雲upload_max_filesize上傳默認2M，修改php.ini 後，重啓apache也不生效，只能重新更換阿里雲系統盤重新配置系統，可是apt-get 缺發生了 E: Unable to locate package *** 什麼命令都不生效，才發現sources.list 數據源出問題了、
這時候需要更新源列表，需要先備份/etc/apt/spurce.list(丟失的話，重新創建該文件)，然後添加新的源。 我用的阿里的，最後執行apt-get update 就可以了
源文件內容：
deb http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse
deb http://mirrors.aliyuncs.com/ubuntu/ trusty main restricted universe multiverse
deb http://mirrors.aliyuncs.com/ubuntu/ trusty-security main restricted universe multiverse
deb http://mirrors.aliyuncs.com/ubuntu/ trusty-updates main restricted universe multiverse
deb http://mirrors.aliyuncs.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb http://mirrors.aliyuncs.com/ubuntu/ trusty-backports main restricted universe multiverse
deb-src http://mirrors.aliyuncs.com/ubuntu/ trusty main restricted universe multiverse
deb-src http://mirrors.aliyuncs.com/ubuntu/ trusty-security main restricted universe multiverse
deb-src http://mirrors.aliyuncs.com/ubuntu/ trusty-updates main restricted universe multiverse
deb-src http://mirrors.aliyuncs.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb-src http://mirrors.aliyuncs.com/ubuntu/ trusty-backports main restricted universe multiverse
